Aristotle was concerned with knowledge of nature, rather than mystical notions, and he regarded logic and reason as the necessary means towards real knowledge. The senses were valued for their use in accumulating particular facts about things, and this sense-knowledge was not thought of as illusory or deficient. Yet sense knowledge by itself cannot produce the general knowledge of science, the knowledge of causal relations and natural laws. Because scientific knowledge also requires logical reasoning to derive, from observed facts, the recurring patterns and principles of nature.

The scientist discovers compositions and causes of things, but Aristotle quested for the causes behind causes, or the eternal principles behind all the various causes and changes observed in nature. These First Principles are the governing natural laws at work in the world, and these Principles ultimately determine the effective physical causes of things changing, as discovered by scientific observation.

As Aristotle generally viewed nature, all living things naturally change and grow in necessary accordance with some inherent formative principle. In other words, there must logically be a natural law or intelligent pattern, within the nature of things themselves, which governs the growth and development of living things. And although the inherent principle within each kind of thing must be different, to account for different things; it must be that all such diverse principles share or participate in one Great Principle. This highest universal Principle, inherent in all nature, would have to be that all living things naturally develop towards a certain predetermined fulfillment, and what makes things be of the same species is that they share the same formative principle.

The different formative principles inherent in the different species are essentially intelligences guiding growth and developments. They are much like Plato’s forms for different general kinds, except that Aristotle always insists that such forms are inherent and embedded in nature itself, rather than existing in some other-worldly hyper-dimension, and Aristotle’s forms are only discoverable by natural observations combined with logical reasoning. But although Aristotle viewed these principle-forms as guiding intelligences, they are not intelligent beings as later occultists will suggest.

Yet these principle-forms can be equated with the soul-mind of species; that is, each species has its own unique group-soul, which is the guiding formative intelligence, or destined end-form, of each thing of the same species. In other words, each living thing is naturally growing towards the predetermined form shared by all other things of the same species. This form is the potential end-fulfillment of any thing, which Aristotle calls the final cause of a thing. But this form is not merely what a thing can possibly become. It is not merely a possibility, nor merely what a thing will happen to become.

The end-form is an actual causal power and guiding intelligence, leading each thing to the end-form itself, though various accidents may prevail and impede the process. The end-form is thus the guiding soul of a particular thing, or the organizing intelligence responsible for a thing’s natural development and potential fulfillment. It is the potential inherent in a thing to become what it shall, given that environmental circumstances support rather than hinder the efficient process towards fulfillment.

So each living thing is both a body and soul, both material and intelligence, and the soul-intelligence basically determines the development and end-fulfillment of the particular body. Each particular body has a soul, but this soul is the same for all bodies of the same species. It is the active intelligent knowledge, or active-knowing (nous) of a species’ end-fulfillment or perfect function, what something ought to become by its own nature. The soul is the spiritual form of any body, the true-form or end-form, the entelechy, the intelligent pattern of potential perfection. This soul-intelligence is the very nature of a thing, and it will determine how something will become. The true nature of anything, the soul, is a fixed intelligent form or predetermining formative pattern; yet though the group soul is determining to its particular body, each particular body may develop somewhat different - due to various environmental circumstances over which the soul has no control. The soul gives a fixed and predetermined potential to the body, but the material- actualization of this potential is not predestined.

Aristotle’s view on forms, in a platonic sense, is that they are general classes of particular things, yet they have reality as well, being formative and organizing in relation to matter. He realized that [platonic] forms are, in one sense, general concepts or universals. In this sense, the form of anything is its general class. Like the form of that thing over there is a horse, while the form of that other thing is a cat. All horses share the same general form, being in the same class, while all cats share a different form. And our knowledge of these various forms is attained by how we realize the different classes of things; that is, we realize the similar essences of things, the similar qualities, the similarity of general forms.

But these forms are not merely concepts, because they have a formative power in the world. In other words, we realize that something is a horse-form, and of the horse-class, but this horse-form is actually the formal intelligence and causal reason for the thing being a horse. So in this other sense, the form is a causal intelligent power, an active soul subsisting within the very matter of any particular body and determining the pattern of development of that material body. So although Aristotle redefines Plato’s forms as being in the world and not beyond it, and as being formal general concepts; he seems to explicate what Plato original thought, that the forms are formative patterns of which particular things express.

Yet Plato suggested that particulars of the world are mere imperfect reflections or copies of perfect Forms existing in the universal Mind and independent of the world. While Aristotle believed that particulars are actual fulfillments of the general Forms, though in various stages of development and to various degrees of perfect fulfillment. He might agree with Plato that few particulars approach complete perfection, but he would argue that this potential for perfection is not impossible to actualize and that the whole purpose of the Forms is to manifest here in the world as particular exemplifications.

Aristotle would also argue that Plato’s theory of particulars copying fixed Forms is misleading, because particulars are the actual expressions of the Forms, the only expressions that even exist. In other words, there are no manifestations of the forms but the particulars themselves. The forms do not actually exist anywhere independent of particulars; because the forms only have a reality in themselves as potentials in relation to particulars. So there isn’t really anything to copy. Particulars aren’t copies; they’re natural expressions of a formal potential.

Aristotle’s view of the relation between forms and particulars is parallel to the relation of potentials and actualizations, as well as the relation of form and matter. Forms are fixed potentials of particulars, and particulars are actualizations of forms. Particular things are real substances, necessarily being both form and matter. Particular things are specific forms of matter, or matter in some kind of form. Form and matter are necessary compliments to one another. They are inseparably necessary to one another. There can be no pure matter without form, no unformed matter, and any matter that we observe is some form of matter. So matter always has a form, or is of a certain kind, and there is no pure unformed matter.

And form cannot exist without matter. Form is always materializing or actualizing in particulars. This is different from Plato’s view that forms exist prior and independent to particulars of matter. Yet Aristotle admits that the forms are potentials in matter, or potentials in material particulars, which guide the development of things, so it would seem that the forms do have an independence. And where, or in what way, do the forms exist? This is not clear in Aristotle, unless we pose a subsistence of the forms rather than an existence, but is the concept of subsistence really different from Plato’s view?

If form determines matter, rather than the reverse, then is not form prior and independent to matter? Even if form and matter universally appear simultaneously, it would seem that form holds its own fixation independently of matter and has an independent power to organize matter. So even though Aristotle’s forms are intelligent causes in nature, it can be argued that they must nonetheless “exist” (or say subsist) independently of material nature in order to be organizing powers of nature, and that their unique reality is non-material and part of a super-spiritual Mind, which seems more platonic than at first glance.

But Aristotle can still be given credit for his emphasis on the inter-significance of both form and matter, as he points out that Plato’s Forms have no logical meaning and purpose without matter or particulars. For the very purpose of such Forms must be to materialize in nature. And we have no knowledge of any forms that we do not find in nature. So the forms are not known by some out-of-body journey of the soul, but are known by observation in the world combined with a rational insight of similarities and differences. That is, we can rationally realize the fundamental essences of things in the world, and we can only discover these essences or forms in the observable world. We may be observing just a particular horse creature, but we can realize this thing as a horse form, realizing the essence-form of this creature to be a horse. That is, we realize the form of a horse; but only when we observe the particular thing.

The form of a thing should not be confused with the perceived shape. Shape and form are related, but not the same. All horses have the same general shape, and this leads to our realization that these things have the same form, but Aristotle does not mean that a form is identical to shape. A form is conceptually known, while a shape is perceptually known. The realized form is conceptual, it’s the general concept of horse. The horse form is conceptually realized, rather than perceptually apprehended, though perception of the particular object is necessary for the conceptual realization. So realizations of forms depend on perceptions, but forms are not merely perceptions.

Aristotle argues that form and matter are inseparably dependent on one another for a coherent description of reality, and his argument is purely logical. The two concepts are a fundamental part of his metaphysics. In a logical metaphysics one must begin with the question of what is real, or what is real substance, at the most fundamental level. But rather than answer this question from just a logical view, Aristotle looks for the answer in what is observable in our world. So, what is real, or real substance, is what is sensibly knowable in this world.

This is different from Plato’s view of the sensible world as less-than-real, in contrast to the reality of eternal Ideas or rationally known Forms. But one could understand the difference here from a semantic view. That is, Aristotle’s meaning of real is different from his meaning of truth. Real is what we find in the world, and truth is what we know of the real. Whereas for Plato, truth is identical to the real. To say that something is real is to say that it’s always true, and to say that something is absolutely true is to say that it is real. So he finds it illogical that the changing world could be real, since it has no stable truth.

But Aristotle’s semantics makes more sense, because the truths that Plato believes are real are not really things. Things are found in the world, and truths are discovered about these things. Truths compose knowledge, but are these truths really like objects? Plato believes so, that absolute truths are real, with real substance and real form, like objects, and that things we find in the world are mere imperfect reflections of these Real-True substantial forms.

Both Plato and Aristotle agree that there are eternal and unchanging Truths, and that these are non-material. But for Plato these Truths actually and really exist, comprised of substance and form. While for Aristotle these Truths do not really ‘exist’ as something, and as knowledge they are in necessary relation to the various things that do exist - the particular forms of matter.

For Aristotle, we know with certainty that things exist, and this is knowledge of the real. But then, what are these things? First, they are material. Their realness as solid things is their matter. We cannot say something is real unless it is matter. That is, reality is material though of different kinds. Second, real things have various forms. Not all material things have the same matter. Or put another way, it is not enough to explain reality as simply matter, like everything is matter, because this would suggest that all things are the same. We observe diversity, a diversity of material things, and this means a diversity of forms, or many different forms of matter. But again, this should not be confused with different shapes of matter. We do observe different shapes of things, but Aristotle’s concept of form is more like general kinds of things - which is, of course, often related to shape.

One of the reasons why Aristotle makes such importance out of the concept of substance (ousa) is to distinguish his meaning of idea and form from that of Plato. Aristotle’s ideas are known from the world of particulars, and they are verified correct by real things, whereas Plato’s Ideas are known independent of particulars and cannot be verified by world phenomena. Aristotle’s sense of form is, unlike Plato’s Forms, actually apparent in this world and emergent from matter. So there is substance to any form, even though some forms are, as yet, potentials of matter. Also, universal forms and particular forms are much more related than in Plato’s system, for we find the universal form actual in particulars, rather than idealized as independent realities for Plato.

The Mover also known as Active Intellect

Aristotle viewed God differently than both the Platonists and Christians. For Aristotle, the Highest Principle and Reality, or the Ultimate Cause of organized matter, is called the Unmoved Mover. It is called this because it moves the universe while never being moved Itself. It is the causal First Principle that empowers motion and change in creation, but It has no cause itself, and no other principle or power is logically prior to it nor before it in time. It is both an Ultimate Cause and an Ultimate rational explanation.

Yet this First Principle is not at all like a Creator-Being or a Father-God with Supreme Will. Rather, it is simply the ultimate Cause and Reason for everything existing. This is known logically because everything must have a cause, even unmanifest potentials, so there must be the Unmoved Mover in order to explain how potentials and actualities ever came to be. Aristotle argued that the Unmoved Mover is necessary to explain actual motion and change, as well as any potential for motion and change, because something [first] Actual must logically be prior to whatever is potential. Thus the Unmoved Mover is pure Actuality without previous potential, something impossible for existing things. In other words, the universe of existences and changes requires an explanation, which must also explain the very potential for all of this; so the Unmoved Mover is the only logical explanation.

Yet the Unmoved Mover is not even the first motion or the first creative force. Aristotle reasoned that existence, or the universe, could not have any beginning, for this would imply that there was a sudden change from nothing to something - which would then imply that the First Principle suddenly made a change or suddenly acted differently from before. But this is not logical, for it would mean that a principle reason for the change existed prior to the so-called First Principle, or it would imply that some potential for this beginning already existed before the beginning. Thus, Aristotle concluded that the very First Principle or Ultimate Cause must be an Actuality without previous potential and that this Principle must be eternal, never with any beginning in time and never suddenly creating time and creation.

The Unmoved Mover is not a physical force on creation, nor does It exert a Will on creation. Yet It is the Highest Intelligence and Cause of created form, in that It is the First Principle behind all other principles of intelligent organization in nature. Things are what they are and become what they shall, due to this Principle, so we can infer that the Mover is the final Intelligence guiding creation. But things just follow from the very nature of this Principle, rather than being willed or decided into existence. So the Mover is a purely scientific Principle of nature, rather than a thinking, deciding Being.

In essence, the Mover is the Great Form, or formative Principle, guiding creation. Things move and change according to this Principle, and the overall creation is being drawn towards this Final Form. That is, things are naturally heading towards their final fulfillment, the perfection of the Ultimate Form or Principle Itself. This is the general view of Aristotle, but he also explains that each kind of thing has its own unique form to fulfill, or the form it is naturally moving towards. An example of this form, called the final cause of a thing, is the final form of man that children may eventually become. And everything has its own inherent final form of potential fulfillment, that it naturally moves toward.

The Unmoved Mover, though, is not the efficient force that actually moves things towards their fulfillment. Rather, It is the Great Principle or natural Law that governs all efficient causes of motion and change. It is the fulfillment itself, or the potential of fulfillment, which things naturally move towards with the help of physical causes governed by this Principle or Form of fulfillment. Again, It is the Form things are naturally drawn towards, the potential within creation that is naturally manifesting in time. Things move towards this Form or Principle, because it is their nature to do so. Though various accidents may impede this process. Aristotle uses metaphor to better explain the Unmoved Mover, in saying that the Mover is like a beloved who moves the lover by being the object of love, by the power of attraction rather than force.


Aristotle is in search of knowledge. But unlike Plato, he firmly believes that real knowledge can only be found in this physical world, and there is no other dimension of truth besides what is in front of us to experience. Knowledge is derived from sense experience and the world, though the natural intellect is also needed.

It is natural for us to want to know about the world. Human beings naturally desire knowledge. Yet there are different kinds of knowledge. The most ordinary kind of knowledge is practical, which is knowledge of how to do things or make things. This knowledge helps us to be more efficient, constructive, and successful in life. For some people, this is the only knowledge of their concern. Yet a greater knowledge is about how things are, and why they are, in particular and in general, for no other reason than just to know. This is knowledge for the sake of itself, though it may later prove to be practical.

There are also levels of knowledge. The bottom level is sense knowledge. This is most direct, and it gives us certainties about particular things. To give examples, one may smell something cooking and thus know this is true. One may burn a finger by touching something and thus know that this thing is very hot. One may taste the fruit of a tree and immediately know it is sweet and delicious. This is sense knowledge, yet our intellect is capable of knowing more about things than that which is immediate to the senses.

The mind can realize connections and relations to different sense knowledge, which can then lead to predictions. For example, after touching a number of hot things, one may learn to see signs of burning heat and thus avoid touching the object. After a wide experience of tasting different looking fruits, one may come to a greater knowledge of what is ripe and what is tasty just by looking at the fruit on a tree. So the sense knowledge of specific experience can lead to a more general knowledge with a practical application of right prediction. This is attained by observing patterns and relations in nature and in our sense experience.

A further level of knowledge can be achieved, which has practical application as well. This is the scientific knowledge of natural causes, or reasons why things behave and do what they do. A person may know that a certain medicine will cure a certain problem, and we might say that this person is a knowledgeable doctor. But an even greater knowledge is about the reasons this medicine can cure, or the natural laws responsible for the medicine’s curing effect on the body. Here one must study the medicine and the body, to find how they relate. This is the work of the scientist, and it gives us scientific knowledge, which is the knowledge of causes and causal relations between things. The knowledge of causes can tell us why things act as they do and change as they do. It tells us why things are as they are and change as they do.

So knowledge can be quite practical but not very evolved or wise. Wisdom is at a higher level from simple knowledge of what is immediately given to the senses or simple information about particular things. The manual laborer needs to know how to perform certain functions, and he needs to have knowledge of this or that kind of wood, tool, etc. He needs to know how to follow certain instructions. Yet it is the master craftsman who knows why this must go here and that must go there, or why this material, and not that, is better to use. He knows the causes between things and how they relate in an overall way. So his knowledge is greater. The greatest knowledge, which is true wisdom, is the knowledge of reasons and principles underlying our sensed world and the changes that go on here. These are invisible causes and natural laws, not directly sensed in our experience of particular things. To attain this higher knowledge of science, we need sense knowledge but also an ability to reason and abstract general knowledge from particular knowledge. The more general and abstract the knowledge, the more universal and wise it is.

Aristotle was concerned with both proof and truth. He realized that a scientific knowledge could not just propose truths. Many Greeks had already proposed varying theories about what the world is made of and how it works. But having a neat idea about the world or its natural laws is not enough. We need some basis for belief, some basis for knowing whether a proposition is true or false. We need some proof, and Aristotle wrote on what is required for proof. First of all, there must be a consistency in the logic, or reasoning, that connects one idea to another and connects real world observations to truth-propositions and theory. Second, the real world has to demonstrate that a proposition is true, that is, we need to find facts in the world to substantiate our theory or our classification of something.

Our truth conclusions about the world or reality must logically follow from definite premises. This means there must be a step-by-step validity in our logic, and this type of logical reasoning is called deduction. It begins from a premise then logically moves to a conclusion. Yet deductive logic, or a deduction, can be valid in its logic even though its premise is not true. That is, a premise may not necessarily be true, as in a false assumption, while the deductive logic remains valid. Therefore, in order for a deductive conclusion to be true the premise must first be true. A proven true scientific conclusion thus requires a true premise along with valid reasoning. So we need a true premise, a starting point for deductive reasoning to a true conclusion. Yet this premise needs some proof. To acquire a proven premise we need an observable fact from direct experience, or else we need a type of valid reasoning connecting observable facts to the premise. Here is where Aristotle differs from Plato, in that he believes facts can be acquired from ordinary observation of particular things. He also believes that true premises, even though general, can be acquired from particular facts. But simply acquiring particular facts does not make a science, for science must speak of general classifications, universal causes and natural laws. So to arrive at general truths from particular facts or observations, we need another type of reasoning which Aristotle calls induction. Our most certain knowledge comes from our senses or direct observation, but our mind of reason has the capacity to acquire general knowledge from particular observations. We can recognize common patterns and characteristics in particular things, and thus acquire general knowledge. We form a general or universal idea of Man from observing particular men, and so too of other animal kinds. This is induction, though it is more like an intuition or direct insight, than a process of reasoning. Then, with this general knowledge gained by induction we can use this as our true premise for the deductive reasoning involved in making true conclusions about the world.

The deductive reasoning is also called demonstrative reasoning, demonstrating a conclusion by a logic necessarily following from a premise. Two truths can then be related, logically, to demonstrate or prove a conclusion that was not actually observed. If we know one general truth and also another general truth, we can deductively derive a third truth. This is called a syllogism.

If A is a true predicate of all B,
and if B is a true predicate of all C,
then it necessarily follows that A is a true predicate of all C.

For example,
If all animals (B) are mortal (A-predicate), and if all men (C) are animals (B-predicate), then all men (C) must be mortal (A-predicate).
If B (all animals) is A (mortal),
and if C (all men) is B (animal),
then C (all men) must be A (mortal).
In a simplifying mathematics: if B = A, and C = B, then C = A.

But notice that we do not demonstrate the premises by deductive reasoning. This would ultimately be impossible, because deductive reason needs premises. So if we had to prove any premise by deduction, we would need a preceding premise which itself would need proof by a premise, and so on infinitely. We have to start our deductive, demonstrative reasoning from some starting premise, which cannot be derived from deductive reasoning. So we need another type of reason that is quite different from the step-by-step syllogism as shown above. This is induction, the arriving at general truths from particular truths, which is an intuitive knowing (nous) or direct recognition of the common essence shared by particular things. Thus, the general truths depend on these common essences -- the common patterns, characteristics and functions of particular things.

Sciences and metaphysics

There are different kinds of sciences, each with its own field of general knowledge. For Aristotle, even ethics and aesthetics, the knowledge of what is good and beautiful, are sciences though admittedly inexact and not as certain as the physical sciences. Each science, or field of knowledge, will have its distinct first principles or underlying laws, the very foundation of wisdom. This knowledge will be attained by abstracting from particular sense experience the general patterns and causes of things. The highest knowledge, or level of abstraction, is about the most general principles underlying all sciences. Aristotle called this metaphysics, which is the knowledge of the first principles underlying all of the first principles of the specific sciences. In other words, metaphysics is about what is common in all scientific knowledge, or the fundamental principles governing all creation.

Each science will seek to know the characteristics of the things of which it is concerned, as well as what is necessarily common to various kinds of things. It will also seek to know the causes for things being as they are and changing as they do, and also how some things affect other things. Metaphysics, though, asks more general questions, such as how anything exists as it is, that is, the universal principles behind everything. It also asks what are the most general, universal kinds of knowledge.

Metaphysics is the study of Being, or existence itself, and the study of higher knowledge itself. For something to actually be, it must have some characteristics or qualities. Everything that is has some form or qualities. Without some kind of form, or characteristics, there is no particular existence. Something cannot actually be, without being some-thing. And for us to have knowledge of something, there must be some-thing or some characteristics knowable about this. So any knowledge of something existing, whatever it is, must be a knowledge of form or characteristic. And our knowledge itself must have some form, for there must be some knowable fact or characteristic about what it is we supposedly know, about the thing we are studying. So any existent thing or event must have some form, rather than being formless. It must have some quality or characteristic, in order to be something. Formless existence without any characteristic whatsoever is simply impossible, or it would simply mean non-existence. And knowledge without any form whatsoever, without any qualifications or predicates, would simply be vacuous or amount to nothing at all, for there would be absolutely no content or nothing known.

Therefore, all things must have some form, and all knowledge must have some form. Knowledge reflects the form of things or the form of that which is studied. We might say that truth is expressed in forms of knowledge that correctly reflect the real forms of things or existence.

True knowledge, of course, comes from a thorough study of particular things, their characteristics and to what ends they are moving toward. Yet we also need to abstract out what is most general about these things and discover what is essential to their nature as distinct from what is accidental. For example, we truly know about horses only when we know the essential characteristics common to all horses, which includes knowing that not all horses are black -which Aristotle calls an accidental characteristic.

As mentioned above, it makes logical sense that no thing, or no existence, can be formless or without any characteristic. Not only do we never find such a thing, but it is impossible to even imagine. Furthermore, a knowledge of something without any form is impossible, or it is a contradiction of what knowledge is, because any knowledge has content or is about something describable. That is, any knowledge is a description or is telling of something - of how this something is, and then maybe why it is this way. Knowledge is something about something.

It becomes obvious that the very language available to tell about the fundamental truths of metaphysics, of what is and what is knowledge itself, is often confusing. Aristotle attempts to clarify these fundamentals by the use of abstract concepts, which do of course reflect reality as it is. His fundamental concepts are substance, form and matter. The concept of form has already been used above to explain knowledge and what any existence must be. Nothing can exist without a form, and no knowledge can be without form. Though Aristotle often uses shape to explain form, his idea of form is not merely shape. Any characteristic or quality of something is an aspect of its overall form. The function of something, as well as behavioral characteristics, are forms of that thing. The thing itself, though never without any form, can nonetheless be spoken of as this thing or that. Yet this unqualified and uncharacteristic reference to this or that, which is the very subject of a description or bit of knowledge, is never something sensed or experienced in itself -apart from characteristics or qualities. In other words, this thing or existence, of which we then speak about or have knowledge, is not really ever separable from the characteristics or form of existence, of which we know it to be. Aristotle gives the word substance for the thing or subject matter, of which we know and describe by some characteristic or another. That is, we are describing and knowing a certain substance, rather than some other substance. We are talking about a certain thing, or kind of thing, rather than something else. What is the subject of knowledge, the subject of our description or proposition, is the substance. A substance will be expressed as the subject of a descriptive or explanatory sentence, while the form is expressed as the sentence predicate.

So knowledge is about substances, existences are substances, and existence in general is essentially substance. In one sense, substance is simply a logical abstraction and never actually found the universe or in our experience There is no actual substance without form. So in this sense, substance is just an abstract concept necessary to the logic and expression of knowledge. But in another sense, substance is the actual material substratum beneath (sub-stance) any existing qualities or forms knowable to us. In other words, it would not be true to say that all existing things are just composed of characteristic forms or properties. This would imply a world without any real material substance. This is agreeable to a philosophical position denying that reality has any physical substance, but it seems counter-intuitive or simply absurd to our ordinary experience. Aristotle could not deny that many things in our world are solid, heavy, hard and tenacious. It is true that these are simply experienced qualities or characteristics, but it is difficult to grab hold of an oak table and deny that it has real material substance. Its hardness and heaviness are, according to Aristotle, forms or qualities, and all that we can specifically know about things in themselves are the forms; yet nonetheless, there is something here making up or producing the hardness and heaviness. There is something of which the hardness and heaviness are characteristics. This something cannot be just a mental abstraction. It must be an actual material substance, which Aristotle calls matter, the material substratum of everything we sense as physically real, the material substratum of the universe. Matter is the general term for any and all material substratum. But matter comes in many kinds, many forms. Different kinds of matter may have different characteristics. For example, oak is quite solid, hard and heavy, while feathers are light, and water is not solid, and some gems are translucent The causes for these kinds of things being as they are, the causes of such characteristic forms, is obviously due to the unique form or characteristic of that composing matter. It’s not because of some transcendental Idea, in which these things participate. The scientist will seek to know the cause of this hardness and heaviness of the oak table, and he will find that this is due to the natural law of its material composition. So we should study the actual matter of things to help explain why things are experienced as they are. Yet material composition is just one kind of possible cause for how things are and why they change, grow or decay. But before moving on to the fundamental causes of things, it will be helpful to summarize


Every existing thing is a particular substance, having some kind of matter and form. Substance refers to actual particular things, unduplicated and unrepeatable. So no two substances can be identical, in the same way that no two things are the same thing. Yet substances can and often are the same in matter and form. The matter and form of things are the common essences of things, the common essences found in the world. In other words, the plurality of repeating essences in our world are the different forms and forms of matter. The different kinds of things are due to different kinds of form and matter.

No substance is without matter and form, while matter and form, as a unity, are the various possible kinds of substance. Matter always has a form, or some sensible characteristics, and form always has compositional matter. There is no primary universal matter, the same in all things. So there are different kinds of matter or material substance. Neither is there just one universal form underlying all things. Rather, there are many possible forms, but not everything has a unique form. Two diamonds may have exactly the same form, as well as matter, though two distinct substances. Form and matter are inseparable in respect to particular existences, though they can be abstracted by the intellect, giving separate kinds of knowledge. That is, although form and matter must co-exist in any thing, neither actually existing without the other, it is still possible to know each separately. Thus, we can know that different kinds of matter may have different forms and different forms may have different kinds of matter.

Matter is not necessarily different in every thing, and neither is the form necessarily different. Many particular things, or substances, may have the same kind of matter and/or the same form. Here Aristotle is a materialist, the scientific sense, yet he denies that there is one essential matter of which all forms and materials are extensions. Form and matter have no actual existence distinct from each other. They are essentially two aspects of particular things, two aspects of substance.

This substance is the particular and unique being of something. The being-substance is the essential is of anything. Or, substance is the something there, that something which we may point to, talk about or describe. In this sense, there are an infinity of possible substances or particular things in the universe of time, each being what is and not being something else. If two completely similar diamonds are set side by side, they are each different things, in that they are different substantial realities. They are different stuff, even though they may be completely the same in material composition and form. They may be the same, in the sense of having the same form and matter, but they are not identical to each other in the sense of being the same actual object. Thus, being two different objects, they are two different substances, two different things. Yet there are different kinds of substances, in the sense that there are different forms of substance, including forms of matter. The different kinds of substances, of matter and form, constitute the different kinds of things. In this way, the different kinds of substantial form are real essences in the world, rather than mere general concepts as argued by later philosophers.

To be something real, or have actual substance, is to have some characteristic form of matter which can then be known and predicated to this thing and to other things like it. Many particular things have the same essential form, or set of characteristics, which means they are the same kind of thing. For things to be the same kind of thing or being, means that they have the same essential form and that the same knowledge can be predicated to them. Particulars are different actual substances, but may be of the same form as other things. If particular substances have the same form of matter and the same form of behavior, then then they are of the same kind of existence. In other words, the general kinds of existences, in which we classify particular things, are based on the common forms of real substance. In this way, Aristotle could truly say that classes of things have substantial reality or real existence, rather than being mere ideas of the mind. In effect, particulars are of the same kind of thing, when they are the same kind of substance, and they are the same kind of substance when they express the same form. This is all logical by the definition of the terms. It might be said that things are the same kind when they share the same form, or when they are in the same form. Yet this might imply Plato’s view, that things participate in forms, such they can share the same form or be in the same form. The alternative would be that things have or express the same form, which would seem a better language for Aristotle’s view of intelligible forms coming out of the real-substance of things around us, rather than universal forms having a super-existence apart from the world we sense. Aristotle appears to have solved a problem, posed by earlier philosophers, of how particular and unique things are related to universal or common kinds of things. Is anything really common or the same in our world? Heraclitus argued that nothing in the world can be the same as anything else. Everything is different and everything is always changing. But for Aristotle the answer to this is definitely affirmative. For Aristotle, and for Plato as well, there are real common essences or universal forms. For Aristotle these depend on the world of particular things and they are in the manifest world, while for Plato they are realities independent of the world of particulars, or the world of differences, though at least somewhat ordering much of this world.

Man is a kind of substance different from the substance of a horse. What Aristotle means, though, is that man has a different kind of behavior and different potentials.

Horses all have the same essential form, or essential characteristics, even though they may be different in non-essential qualities such as color or size, and they be slightly different in shape. These differences are called by Aristotle accidental forms. A horse is black or white by a non-essential accident of nature. The actual color is non-essential to the kind of being it is. The color may vary, which shows its non-essentialness, but much about horses is the same for all horses, such as the way they run and other distinct behavior, and their overall shape which we do not confuse with any other animal. If we imagine seeing a bunch of these animals for the first time, and have no name for them, it would still be quite obvious that they are all essentially the same. We know they are the same kind of animal, because we apprehend their common essence which is their common form. We do not see any formless substance, nor any formless matter; we just see various forms or characteristics and we can intelligently apprehend the essential forms that are common to all.

Each horse has a distinct color which is not separate from its essential being in this particular case, but the accidental color is separable by the intellect abstracting the essential knowledge of what truly constitutes the essential form of this kind of being. The intellect can abstract and know the necessary essences of a kind from its accidental properties. The intellect can know the essence of all horses, or that which is common to all horses, before Recognizing that a particular horse is black or white. Yet the accidental properties of a horse are sensed together with the essential properties. So the common essence or form of all horses is independent, as far as knowledge goes, from the totality of properties found in particular horses. The essence is independent from the accidents. The whole totality of properties form a particular unity, an individual horse, but we can recognize what is essential to all horses from what is non-essential or not necessary to horseness. Aristotle realizes that this knowledge is not a logical deduction derived from a premise or definition, such as what all horses must be. Instead, he calls this knowledge an induction, rather than a deduction, and it is derived by a natural intuition about what is repeatedly common to particular things. By Recognizing the common essence of things, we are then able to formulate a definition of all horses, which can then be used as a true premise for deductive reasoning and the making of conclusions about how kinds of things relate. Science will build from our knowledge of causal relations between different species or natural kinds, finally arriving at the general laws underlying these causal relations. Yet true conclusions will depend not only on deductive logic, but also the truth of its premises -which can only be derived inductively by proper study of many things. Useful deductive logic can only follow from true premises, which can only be known true by sound inductions, which require keen observation and an intuitive ability to recognize what is essential, necessary, or always common to a general group of things.

Forms or qualities, found in the world of things, are not without substance. The substance underlying form, or making up form, is matter. Thus the world is material substance, which is matter. But talking about matter as one primary substance is an abstraction of the intellect. Every found form must be of some substance, so in this sense the world of form, the world we perceive, is made of material substance. But not all of this substance is the same, meaning that not all matter is the same. There are different kinds of matter, which is another way of saying there are different forms of matter. Aristotle assumed no theory about one universal, primary matter. The matter is obviously different in some things. This is evident to any sensible person, and a craftsman can form similar shapes from different material/matter.

It’s not that things have substance, but that things are substance. And each thing is a substance of some kind or form. Each thing is unique as a particular substance in a particular time and place. Yet Aristotle believed that every thing-substance has some form, or another, which is common to a larger group or class of things. Everything will fall under some logical class, or another, because of its form. There are many different forms in the world, but not all forms are different. There are common forms in the world of particulars And here is how Aristotle maybe solves the problem of commonality in relation to diversity.

Logic, language, and analysis

In language we link ideas together by how things are really linked together. We know how things are really linked together by an inductive reason, and we make further linking truths by a deductive reason. We need to begin from ordinary observation, or sensory knowledge, then inductively attain general knowledge, then from general knowledge deductively derive further truths regarding the necessary relations between these general truths. In this way, a whole system of knowledge is developed.

Aristotle viewed logic as the intellectual instrument with which to formulate a language of scientific truth. Basically, logic is the structure by which a language of truth can correctly mirror the reality of the world. Three fundamentals are in relation, in respect to scientific truth: the world as it is, the language that we use to express truth, and the logic of the language which ought to reflect the underlying structure of reality and change. Logic mediates the real world with a language of truth.

The question is, “what can we state in language about what really exists and why this exists as it is?”

There are different kinds of things in the world, and each kind has its own characteristic form of being and behavior. We find very general groups of things with the same essential form, and in each of these very general groups we may find groups of a less general nature. This process of analysis can continue further, as we divide the more general into groups of less general. At each lesser level, the essential common form to those group members will be more specific and more exclusive, though they will nonetheless and necessarily hold the general form of the more inclusive level that is logically above. For example, in the natural world all animals have the same very general form, some very general but essential characteristics. Yet in this large grouping, or class, are many less general groups or less general forms of life. Here we have different species of animals. Also, more general to the class of animals is an even more inclusive class called life. Not all living things are animals, or have the same general characteristics as all animals have. So we find in nature a natural hierarchy of living things. There are different genera of life, such as animals and plants, and then different species of animals and plants. We can even fit in a middle level of general form, between animals and the more specific species, such as mammals and fish. The names we give to these levels is not really important; what’s important is the recognition of the levels and groupings, and a definition of each kind that correctly reflects the true similarities and dissimilarities of things. Also important are the two fundamental intellectual processes involved for discovering what is higher or lower in the hierarchy, or what is more inclusive and less inclusive. We use analysis to divide larger groups into smaller groups, or to find more specific characteristics common to certain groups within a greater group. In an opposite process of reasoning, we use abstraction to ignore the more specific dissimilarities of things and recognize the more general and inclusive similarities.

Also, and by abstraction, we can know the general categories of all characteristics. These are the categories for how things are and how things behave, the categories of description. Every substance, or known thing, has some characteristics which are expressed as predicates in descriptive statements, and these can be categorized into general types. Aristotle lists nine categories, including quality (how something behaves), quantity (as in how much weight), relation (as in perceived proportions), place (where it resides), time (when), posture (standing, still), possession (what it contains or the outer skin), and action (what it does to other things).

The main idea here is that science must ask certain questions about anything, such as where, when, how is it, and how much. Predicative knowledge, or what we say about things, can be classed in these general categories. So the categories are the basic predication concepts used in scientific inquiry. The knowledge we find about things are the forms and relations of things, which includes quality, quantity, posture, etc. So Aristotle is simply categorizing these types of forms and relations, at the highest level of abstraction. Again, there is no existence without form and matter, so whatever exists to our knowledge must be known in some way or form, or by some predication. Yet the predication categories are not merely mental constructs, for they do abstractly reflect the very principles of existence or how things really generally are.

The things of existence, most importantly living things, have causal reasons why they exist in their peculiar way. Here Aristotle is wondering why certain kinds of things are as they are, rather than being something else. He is still thinking with abstraction, but his concern is more down to earth, and scientific, than previous thinkers who often asked the most abstract questions, like why there is any existence at all or what caused life in general.

Four "Causes"

Two important questions asked by Aristotle are, why something is the way it is, and why it changes during the course of its existence. There must be an explanation, and this is the aim of science. Aristotle gives the following four [kinds of] causes, or causal explanations, though keep in mind that he is primarily thinking of living things.

1) Formal cause - the general form of it; which also leads to class 2) Material cause - characteristics of its matter.

3) Efficient cause - forces effecting its becoming.

4) Final cause - its inherent pattern towards which it is becoming.

In other words, to explain how something is or behaves, and how it changes or develops, we need to find answers to the following four questions:

1) What kind of existence is it, or what is its general nature? Knowing the general nature of anything is a knowledge of form. So we can ask, what general form is this?

2) Then we might ask, “what material constitutes this form? What is this made of?

3) What are its instrumental causes; what movements are producing change or development?

4) What is the final fulfillment inherent in this? What is this naturally becoming or changing into? What is its final end?

These questions, or the Four Causes, are intrinsically related, rather than being separate possible causes. There is often confusion about what is meant by the Four Causes, so it will be helpful to clarify what is and is not meant.

In one sense, Aristotle’s meaning of causes is more broad than our ordinary meaning today. Rather than cause being simply a force or object affecting something else, Aristotle’s meaning can be interpreted as an explanation for anything being the way it is, as in “what are the explanations [causes] of this being this way?” Yet mere explanations do not necessarily imply actual happenings. If we just said these are four explanations, it might be thought that there is not necessarily anything real about this, since explanations can just be in the mind or in theory. But Aristotle definitely believes that the Four Causes, though general abstractions, are basic kinds of facts --about what is really going on or about what is really affecting the relative permanence and change of things. So in this sense they are causes, or causal explanations.

The idea of a cause may bring to mind the impact of a hard ball on a glass window, the ball causing the window to break. This kind of cause produces change, but it isn’t what Aristotle means. There is also the example of someone causing me to be angry, which produces change in my reality, but again, this isn’t an appropriate example for what is meant. Only one of the four causes, the efficient cause, seems to be like our ordinary meaning, like a ball causing glass to break, or strong wind causing a sailboat to move fast.

Yet this more modern meaning of a cause is not appropriate to any of the Four Causes, not even the efficient cause. Though Aristotle’s efficient cause is closest in meaning to our modern meaning, it has a more limited meaning, because it only refers to causal relations within specific living things, or just within a specific species. For example, there are movements and changes going on in a chicken egg that are cause to its growth. Movements in the things themselves are somehow responsible for the recognized changes or growth of these things. Here are the beginning principles of biology.

Aristotle is only referring to movements and causal changes within the thing itself, not external movements that might cause change. It is obvious that change is produced in the life of a chicken when it is grabbed and eaten by another animal, but such obvious external causes of change, which might be called accidental causes, is not what Aristotle means.

Later scientific theory describes important external causal factors in the growth of a chicken from its egg, such as an adequate environment surrounding the egg. The surrounding environment or ecology of any living thing is important for survival and growth, and we can think of these external factors as causes. But Aristotle is not thinking of external or environmental causes. The meaning of his efficient cause is confined to the biology or physics of the thing itself, as in what are the causal factors in a thing responsible for its natural change, or what is actually moving in the thing to produce the changes. So his meaning of efficient cause is about the internal movements of anything, not external impacts.

Another confusion is the meaning of formal cause. With the formal cause, it seems odd to say that a thing is how it is be-cause of its characteristic form or basic design. Isn’t this a circular logic, or a truth by definition? It’s like saying that a four-leaf clover has four leafs be-cause it has four leafs. How the plant is is the same as how the form is. It is even worse to say that a four-leaf clover has four leaves, be-cause it is that kind of plant classified as a four-leaf clover. This is not only circular but even seems reversed in its logic. The cause of a clover having four leaves is certainly not found in the formal classification, and there is no way that Aristotle would have made this ridiculous mistake. It would make at least some sense to say that a plant is classified as a four-leaf clover because it is a clover with four-leaves. In this sense, the plant’s form may be said to be ‘a cause’ to the plant’s definite classification. But if this exemplifies Aristotle’s meaning, then his Four Causes are ‘causes of classification’ rather than causes of actual being or changes. They would then be better called reasons for formal classifications, such as the reason for classifying something as a four-leaf clover, while the term ‘cause’ isn’t quite appropriate. So if this isn’t Aristotle’s meaning, then what could it be?

The key to understanding his meaning is that the Four Causes are not separate from one another, as we might tend to think. Each of the Causes are intrinsically related, that is, each one implies the others as well. They are like four aspects of how anything is what it is and changes in the way it does. He is not suggesting that these are four separately possible kinds of causes. So the form of anything is intrinsically related to the nature of its matter, its growth and its final design. In a general sense, then, the form of a thing is a cause of its being and cause of its changes, or the form is a causal aspect of being and change. The form of anything makes it what it is and is part of the causal explanation for its development. A scientific knowledge of the dynamic nature of anything would be incomplete if there were no knowledge of form. If we are to scientifically understand the whole nature of something, the whole of how it is and behaves, including its function in relation to other things and including the form of its natural destiny, then we need to take in account the form. So for these reasons, Aristotle had to include a formal cause under the general category of Causes or causal explanation for how things in the world function and behave as they do. Without knowing the form, we cannot understand the process of change and development.

The efficient causes are the affective, modifying, internal movements that make change or growth. That is, change or growth does not simply occur without something moving internally. If form A changes to form B, or in any slight change of form, there must be a causal movement involved in the change, or some effective motion proceeding the change to form B. There must be a movement in form A that produces the change from form A to form B. So Aristotle is supposing, quite rightly, that efficient cause-effect relations are going on in the bio-matter of any living thing, which is what makes the growth and change of form occur. Yet the efficient cause is not completely explanatory. In order to understand the causal relations in the bio-matter, we will have to understand the present form and matter of this thing. We must also understand the end-design inherent in this thing, in this form of matter. The end-design, or potential of fulfillment of a thing, is somehow inherent in the bio-matter itself and is the ultimate cause of all efficient causes going on in that thing. We could go on and on showing logical connections between the four causes, but the point is that these four causes are intrinsically related and are not merely separate kinds of causes.

The efficient cause is a movement kind of cause, as when parts of something affect other parts. It’s like one part bumping into another, causing that second part to bump into a third part, and so on. Aristotle believed that any change is a process of movement, and any movement must have been efficiently caused by a proceeding movement. Thus, there is a chain of events, or movements, which causally proceed any present and future movement. This chain of movements would, in theory, have an infinite history, that is, we could follow the chain back indefinitely until we reached the beginning of time or until we reach a logical First Cause.

First Cause

Aristotle suggests a logical First Cause which he calls the Unmoved Mover. The Unmoved Mover is the logical cause of the universal chain of causal movement or efficient causes. But it isn’t like a God first creating movement or giving a first shove at a static universe. The Unmoved Mover is much more subtle, and so is this causal logic. The universal chain of efficient causes is causally explained by the Unmoved Mover, as a kind of first cause; yet, the Unmoved Mover is really the ultimate Final Cause, being equivalent to the overall End-Design, Destiny, or Purpose of universal existence. The Unmoved Mover, which is Aristotle’s concept of the ultimate God, is sort of a creator God except that this God is really the Intelligent Power luring life to its potential fulfillment. The Unmoved Mover is really the Final Cause, the Final Design or Final Purpose, which is somehow inherent in the universe throughout all infinite time, and which influentially draws life to its final good or fulfillment. The Unmoved Mover, thus, lures life to move towards its potential fulfillment, the perfect functioning of its potentials, towards its final end-form. This final potential perfection of something is its final cause, which is also the ultimate explanation for its growth or advancement. And the ultimate Final Cause of all particular final causes is, of course, The Unmoved Mover as the explanation for all movement-growth and advancement of form in our world. The Unmoved Mover is uncaused itself, yet causes the whole chain of universal movement towards final perfection. So life has an inherent destiny or purpose, which is the ultimate cause of movement. The Unmoved Mover is active and moves, but isn’t moved by anything else. Aristotle thought that such an Unmoved Mover was logically necessary to explain both potential and active motion. To explain motion and the inherent potentials of life, he thought it necessary to assume that Something is Moving logically prior to all motion, and that Something is Actual logically prior to being potential. Yet he does not mean that the Unmoved Mover is simply like a creator-god or first-cause, because It doesn’t push out on things or throw out the universe in motion. It is not simply an ultimate efficient cause, like the first moving domino creating a chain of hit dominoes It works, rather, as an ultimate Final Cause or Final Aim, which is described by analogy as like the beloved who moves and advances the lover just by being the object of love and the power of attraction.

The Unmoved Mover is also the Active Intellect of the world. It is rational intelligence itself, always being rationally intelligent, always functioning, always at work, never asleep or not functioning. This Active Intellect is the Soul of the World, the guiding intelligence of all things, but not necessarily functioning or active in things. Life has the Active Intelligence in potential, as World Soul, but not necessarily active or actualized in the individual lives. Just as the human soul contains the potential of human fulfillment, the Soul of the World contains all potential for the whole world’s fulfillment. The unending activity of the World Soul, the Active Intelligence, is unfolding in our world from potential to actual.

What we have here are three levels: Active Intellect, human soul, and embodiment. There is the Active Intellect, same as the Unmoved Mover, being Rational Intelligence itself and the Gnosis of final good or fulfillment. This is the Soul of the World, bringing intelligent design to the world. Then there is the human soul, one in essence but plural in the plurality of human bodies. This human soul contains the full potential of the Active Intellect, and its true function is rational intelligence, but this soul is a potential that is coming into actualization, rather than being necessarily active or actualizing The actualization of the human soul, the rational function, is relative for different bodies, being actualized in some bodies more than others. The final fulfillment of the soul is to be fully active, functional and actualized, which means being fully successful at performing its true function - to rationally, intelligently organize the physical life... in the most balanced way possible.

The soul of a body is its intelligence, including its end-design as potential perfection. Each life is striving to fulfill its particular entelechy, the completeness of its inherent potential, and this entelechy is somehow in the body or biology itself. A body will have its particular chain of causal movements, or efficient causes, yet these are ultimately guided by the entelechy or final cause. And the greater universe, or world, follows this same principle involving the final cause with movement and change.

When the body dies, its soul ceases to be individual and returns to being the general human soul. It was only ever individual in relation to a particular body, because the soul is the potential intelligence which is, in essence, the same for everyone. All that is really immortal and undying is the Active Intellect of the World Soul, for this is the true source of any human potential. Thus, human souls come from the Active Intellect, or we could say that they are potentials of this Active Gnosis. And if all human bodies die, there would be no remaining discarnate souls, yet there would remain the Active Intellect.

Active Intellect

It could be argued that the Active Intellect logically implies a non-physical realm of ideas, similar to Plato’s belief. Afterall, the potential intelligence and perfection of the human psyche is what is known by the Active Intellect. That is, the Active Intellect would not only be an actively functioning Super-Intellect, but must also have continuous gnosis of final ends or perfect forms. If our intellect knows a truth, this truth must already have been known. If our intellect has a potential to know something true or a final end, then this potential knowledge must already be known, or it must already be knowledge in some realm besides mere potential. This sounds more and more Platonic.

The very reason that Aristotle supposes there to be an Active Intellect, transcending the world, is his need to logically explain the genesis of potentials. In other words, Aristotle was asking, “from what come the potential perfections, or how do the entelechies arrive in the realm of potential? His logical answer is that potential perfections, or entelechies, must already be in an active Nous (Mind), which he is calling the Active Intellect and World Soul. In his logic, there must be an active-knowing a priori to potential knowing. Many religious philosophers will later agree, that in order to explain potential perfection and advancement of the rational intellect, we must necessarily suppose the existence of a Supreme Mind having gnosis of what is potential in this relative world and gnosis of the potential perfection towards which we are headed or meant to strive. Yet this kind of reasoning, that there must be an Actuality a priori to any potentiality, would seem to lead to a Platonic, transcendental realm of Ideas, which is what we thought Aristotle wanted to avoid.

Everything has an inherent way of being, which leads to a final end or fulfillment. We can suppose, then, that everything has its own possible perfection or fulfillment of its being. Aristotle believed that everything had an inherent design, or intelligence, which moved it toward its final fulfillment or destination (destiny), though other factors could come into play that might alter its natural course. Everything has a built-in design for behaving and changing, which leads a thing towards its potential final end or limit of what it can possibly be. Each kind of life or existence has its inherent potential design or built-in potential, though the actualization of this is not predestined in the sense of being guaranteed or certain. The self-contained end of anything is called its entelechy.

Potential, Soul, and Intellect

Aristotle distinguishes potentiality from actuality. Natural change is a process from potentiality to actuality, as the potential end-design internal to something actualities into manifest existence. Things are in a process of fulfilling their special potential, which is shared by other things of their common kind. One could say, in a sense, that the end-design is inherent in something before this design is fulfilled or actualized, as if the mature oak tree were inherent in the acorn seed. In a similar way, the advanced intelligence of a mature human is inherent in the baby child. All of the potentials of what a person can be are inherent in that person prior to actualization

This potential, end-design, or final cause, is really inherent in the matter or body of a thing. The matter of something has in it a potential form or design of its final aim. It has a potential actualization of final form before fulfilling this form.

A potential form is inherent in matter as a kind of intelligence in things which knows the end-design and leads the matter to its final end. This intelligence in a living body is the soul. The soul of a body is knowing form of its matter. In other words, the body has an intelligence of its potential form of being, of what it can and is meant to be, and this is the soul. The soul is the formula or design for a being’s fulfillment. The soul is distinct from the body, as form is distinct from matter, yet Aristotle says that without the body the soul could not exist. The body is the actualization of the soul potential. Here again there is the inseparableness of form and matter, and the necessary relation between potentiality and actuality. The body gives existence to the soul, just as behavior gives existence to intelligence. So body and soul are a unified relation in man. No body without a soul, and no soul without a body.

Aristotle says that the individual soul comes into being with the physical body and disappears with the death of this body. The soul is the body’s rational intelligence, and man’s potential for final fulfillment could be said to be in the soul. When the body dies there wouldn’t be any meaning to an individual potential or inherent intelligence. The soul, for Aristotle, is not really individual at all, except in relation to an individual body and life-span. Each soul of a human body is none other than the one true human soul, which is the intelligent and rational potential of any human being. So everyone is born equal, since everyone is born with the same human potential, the same essential soul. What we each make of our common potential is of course different, though it is unclear how Aristotle might explain the obvious differences in people’s moral behavior and in their differing abilities. Why is it that some people are more rational and some more irrational, if we all begin with the same slate? Aristotle would explain differing abilities by biological inheritance, mixed with social education.

Yet, though Aristotle rejects Plato’s belief in a reincarnating soul, he seems to maintain Plato’s basic idea of the soul as being the source of our rational intelligence and responsible for our rationally good behavior. Yet the soul has two parts, the irrational and the rational, so it would seem that the soul is also responsible for man’s irrational behavior. The irrational part has two subparts, the vegetable part and the desiring appetitive part. This again follows Plato, though the vegetable part is described as being the cause of living vitality and the intelligence of the functioning body. It does seem odd to view the soul as both rational and irrational, but this makes more sense when we realize that these philosophers were generally speaking about the whole psyche of man, and man does exhibit both the rational and irrational.


Aristotle’s ethics, which is quite coherent, involves the rational function of the soul. The significant function of the rational soul is to rationally control and guide the irrational part. Aristotle does not say that desires and appetites are bad or contrary to the good life. His ethics do not suggest a whole scale elimination of physical desires and worldly pursuits of wealth and success. In fact, we should go for all the happiness we can get, though without harming others. The good, or virtue, is the fulfillment of happiness, and happiness is the fulfillment of excellence. Morality has nothing to do with passivity, being pious or worshiping gods. It is not like the kind of virtue we associate to religion. Virtue is excellence in life and the fulfillment of our inherent potentials. This excellence is our potential fulfillment, as known by our soul. It is to be all we can be. Yet this requires control over the irrational desires, for the irrational has no overall view of our whole potential fulfillment. Desires are one-pointed, racing towards one goal, but seeing or regarding any other goals. So rational morality is not a matter of eliminating our desires, but rather a matter of organizing the desires in a balanced way and not allowing any one or two desires to dominate the life. Each person should be like a just society, where no one gains the complete upper hand and where all people are considered equal. Of course Aristotle would consider intellectual desires superior to sexual desires, but the main point is that we can achieve most of what we desire if, and only if, there is a rational overseeing and organizing of all the desires. Also, Aristotle rejects Plato’s belief that knowledge of the good will necessarily lead to good action. People may know what is good overall for their greater happiness, that is, they may have a rational knowledge of what is good and excellent; but nonetheless, they may still do what is contrary to this knowledge. This is because of our behavior habits. Action will simply follow the habits of our non-rational nature. So if we want to change behavior we ultimately have to change our habits. But the irrational nature cannot change its own habits, anymore than nature itself can change the way it is. Therefore, the rational soul, being above and independent of the irrational nature, is needed to make changes in our old habits. The rational intellect, that part of our psyche or soul, is needed to know what is the better good for man and how to best organize the desires and behavioral habits. It function, thus, is two-fold: to know the better good, the most excellent way, as well as the final end-purpose of man; and also to enact the practical work of actually changing habits and actually doing what is needed for final fulfillment. So the rational soul is not only the moral knower, but is also the efficient agent for moral change and fulfillment of the good life.

Man has a distinctive end to achieve and function to fulfill.

The human psyche has a higher and lower nature, the rational and irrational, yet the human being has the potential for not simply following its irrational habits of nature. Our lower nature is like an animal nature incapable of functioning in any other way than following its inherent habits of nature. Although we can acquire added habits, depending on our irrational impulses and the conditioning of our society. Like an animal, we can be trained in new habits. A domesticated dog is not just following its inborn habits. If we think of our lower nature as a dog-like nature, our rational nature can train the dog to have new and better habits. This is how the rational soul should relate to its irrational nature, by training and organizing it.

Desires will need to be sublimated at times, but not destroyed. The rational soul aims at balancing desires into a harmonious order or proportion. Even the human qualities that might be regarded as good in themselves, like courage or humility, need to be balanced by their respective opposites. A man of zelous courage will eventually act foolishly unless balanced by caution. A man of extreme humility will never unfold his potentials unless balanced by a self-confidence. The goal is excellent achievement in life, tempered by a devotedness to social justice. So moral good is not a denial of individual achievement, nor a denial of worldly or physical desires. It is, rather, a balance of self-excellence and social justice. There are no fixed rules in this moral principle, like clear instructions or commandments to be religiously followed. Each person must intuitively find the right balance, though following the general principle.

The most perfectly good behavior, or virtue, is rational behavior which is an extension of rational decision and the will-to-enact. There are no set ideas of what is good behavior. It is, rather, a following of the general principle of rational decision. Also, there is no opposition between rationality and all desires; rationality is just in opposition to any one desire taking authority.

The ultimate and greatest desire, or aim, is happiness because happiness is what all of the desires aim toward. Happiness is thus the apex of man’s fulfillment and the ultimate aim of the rational soul. Happiness is what all desires aim toward, so happiness is good in itself or good for its own sake. Happiness is an intrinsic end, while the other desires are instrumental ends to happiness. Aristotle recognizes that most of our aims or desires are not ultimate aims in themselves but are merely instrumental to further aims, and the ultimate final aim is none other than happiness. Thus happiness is the ultimate good, because it is desired for its own sake and is instrumental to no other desire.

Happiness is a general feeling of fulfillment, yet happiness may come in many forms, or in many ways. Many desires all seek happiness. But the Greek word actually used by Aristotle is eudaimonia, which might be better translated as the final good for man by the fulfillment of his greatest function. This final good, or greatest fulfillment of function, is rational thought and behavior. So his sense of happiness, ultimately, is not merely success or attainment of material pleasures. Yet these achievements may be part of the happiness in fulfilling our rational function, because our rational function is to organize and balance our many desires and achieve as much as we can. In this, though, we must not let a few desires cloud our rational function and take control over our decisions and actions. The final good, then, is happiness through achievement and excellence, by the right use of our rational intellect to organize and direct behavior.

Metaphysics revisited

Metaphysics is the study of substances and causes. Substance, for Aristotle, means being, or that which is actually real. So the study of substance is the study of what is actual or real. In talking about things, or in talking about universal truths, we use ideas. Yet there is more to truth than mere ideas. There is the reality of which ideas describe or allude. Plato had suggested that the universal Ideas were real and that particular things only reflect these Ideas more or less. In fact, he thought that particular things had no real substance, besides the Ideas in which they participated, though this phenomenal world of appearances was regarded seriously by Plato. In contrast, Aristotle holds quite a different view on what is ultimately real, which is that all universal ideas are about particular things, though not the same, and ideas have no meaning apart from being either potentialities or actualities of the ever-changing material world. True ideas are true only if they tell us right about what is real, and what is real is what exists all around us. This reality, in its many possible forms, is the real substance. So there has to be real substance for actual truth. This substance is reality, in the logical abstract sense, but in the particular sense, substance is whatever anything really is, and this can be any form-of-matter whatsoever. For Aristotle, then, this sensible world is the world of substance, and however grand an idea may be, it is still only meaningful in relation to this real world of substance. Substance always includes matter and form, while for Plato the immaterial Forms might be said to have real substance though independent of matter.

The transcendence of Plato’s Forms from particular things, or substances, might have seemed a logical solution to the question of how universal ideas remained permanent while particular things differed and changed. Yet Aristotle suggested a different solution without any need of this transcendence. Universal ideas are related to their particular examples in the following way. All of the appropriate examples, in respect to a uniform idea, have the very same substance --which is the real substance of that idea. Each example, as a whole, does not necessarily have to be all of the same substance as its other members of that idea. In other words, the examples are not all the same, or exactly the same, so there can be some difference in their overall substance. But if they truly are examples of a certain idea, they must all have at least this substance in common, the substance to which the idea refers. Remember that a true idea is only true if it has real substance, that is, if it refers to something actually real.

What makes different chickens all chicken is that they all have a chicken substance - whatever that is - which is part of a scientist’s question and study. Things that are truly tables must have at least something of significance in common. Otherwise, we could not know the truth of something, like a table. We could not know how to distinguish things that are tables from things that are not. If we are going to find truth, we must find it in the substance of this world, in the substance of particular things. Whatever is significantly in common to things and substantiates their common idea is known as the real essence of those things. What is common to all tables? What is common to all chickens? To discover this is to know the essential substance to which those generic ideas refer. This essential substance, or essence, is not necessarily a common material substance. This is not what Aristotle means. All substance is matter and form in relation, or a form of matter, so it is easier to understand the common essence of things as common forms, designs, or functions. It is not simply being said that what is common to all chickens is chicken meat. We are talking more about form than matter, though matter is relevant since form cannot be actual without matter.

The essential substance of a species is found in all or any members of that species. So the idea of that species is directly related to the common substance of its members We can find real substance to the idea. The idea has a real essence. The idea is founded in the real substance of things. It might even be said that the members of a species share a common substance, but again, the meaning here is not like a shared chemistry or material substance. It is a shared essence of form, which is, for Aristotle, more like a functional structure of matter-substance than a kind of matter.

If Socrates is a man, then he must have some essential-substantial form that is the same for all men. Man is not just a mental idea or mere abstraction of the mind, for man has a real substance. The essential substance-form of man is rationality. This doesn’t mean, necessarily, that all men and women are rational; rather, it means that all humans have the given potential of rationality, and if they don’t they aren’t really humans. The common essence-form of man is man’s final form, or the greatest potential of man, which is his soul-given rationality. Rationality, which Rationality is the form of man’s substance, the real essence-form of man. ..... Chickens have a different common essence-form, different functions and features. Usually the final form is the common essence of a general species, and this final form is a thing’s potential for final excellence, final achievement of function, or being as perfect as it can possibly be according to its nature. For man this is rational thinking and behavior. For other species it is something else.

Things which have the same final ends, or potential excellence, are of the same species. Particular things have features and or functions in common with other things, which are the basis for classifying these things in a common kind. They have the same universal form, the same formal essence, so they are known by the same universal name or the same name of species. Or if they do not have the same actual form at a certain time, they may still be of the same species if they have the same final form or potential function.

Thus, the substantial essence of a kind or species, and what is common to all members, can be logically addressed as that which is both necessary and sufficient to something being truly of a certain kind. If an essence is necessary to a kind of thing, then all that is truly this kind of thing has to have this essence, and if this essence is not found then the thing cannot be of this kind. Knowing that an essence or form is necessary will thus limit and exclude other kinds of things from this class. If an essence is sufficient to something, then evidence of this essence is proof of this thing being of this kind. So knowing that an essence is sufficient will thus include and determine things of this class. Later philosophers either speak of just essences in the definition of classes or make a firm distinction between the essence of a definition and the real essences (or properties) of things in this class. But Aristotle seems to refer to real properties, or at least potential form, as the essence common to things of the same class.

more on essence

In Aristotle’s metaphysics, forms repeat themselves through any number of particular objects. It would be a mistake to think of these forms as an infinite number of possible shapes, like all possible shapes of embodiment. Particular things do not need to have the exact same shape and measurement to be recognized as the same form. Form and measurement are not the same. Humans have slightly different measurements, yet they have the same human form. People may have different exact abilities and functions in life, yet have the same formal capacities and function of the human being.

To use a geometric example, there are many possible objects having a round form, yet these objects may differ in their exact measurements, and they do not need to be perfectly round in order to generally round. In fact, ‘perfect roundness’ might not ever be found in the world of particular objects, yet roundness is the common form of all things nearly round. So any form, in the way that Aristotle means, is recognizable in particular things but not necessarily perfect in those things. The form is a kind of potential perfection, or ideal possibility, which is more or less actualized through particular things.

This of course sounds rather Platonic, and it is, but Aristotle at least emphasized that the human intellect can naturally recognize the common forms of particular things, even though these forms may not be perfectly actualized Also, the forms have no meaning, nor existence, apart from this world. Plato might then counter argue that the forms must exist independently of this world, this world of particular things, because they are never found in particular things in the perfect way that they are intelligible to the mind. How can we possibly conceive of perfect roundness, or a perfectly balanced rational life, if we’ve never observed these in the world? Plato’s answer to this puzzling question is that if possible perfections are imaginable by Reason but not actually found in this world, it must be that these possible perfections exist in an immaterial world of Reason.

But returning to Aristotle, the forms are found in this world of particulars, though not literally in their complete perfection. Like Plato, Aristotle is saying that the forms are not actually immediate to the senses, not actually apprehended by observation. For observation only yields an immediate knowledge of particular facts or particular measurements. Yet unlike Plato, Aristotle argues that our accumulated sensory knowledge of ever-changing particular things leads the intellect to an insight regarding the ‘universal forms’ of particular things. This insight way of knowledge is called an in-duction, and it is distinguished from a reasoning-process called de-duction. Aristotle would have probably argued, against the Platonist School, that universal forms could never be known without sensory experience or without our knowledge of particular objects. It is also probable that some Platonists developed a more mystical school emphasizing the attainment of universal knowledge by mind alone, withdrawn from the sensory world of particular things. This would be a path far removed from Aristotle’s view.

Particular things, then, usually are somewhat unique from other particular things, in their exact composition and measurement, and yet they share with other particular things at least one identifiable common form. The common and recurring form of things would be the intelligible essence, or essential form, as distinct from the accidental-unique shape or behavior of these things. So now we have a distinction between recurring forms (or universal essences) and accidental differences of particular things. The form-essence must be recognized in order for a particular thing to be identified or classified as a certain kind of thing. That is, in order for something to fall under a certain concept, or conceptual kind, it must necessarily embody or express some kind of form-essence. The formal essence, thus, logically determines what kind of thing this is - or what we know it to be - or what we say it is in language. The essence is what an object must express in order to be necessarily and sufficiently identified as a kind of thing, or identified by a certain concept.

Hobbes and some later empiricists will argue that there really is no such form-essence common and recurring in particular things, but merely common essences of word-definition or essential rules for determining the class-name of particular things. This will be called nominalism, whereby particular things of the same general name have nothing exactly in common except for their shared inclusion in a common class-name under a common set of rules for determining their common name. The universal essence, then, reduces to mere essences (or rules) in a definition of a general name. Yet even the nominalist has to answer the question of how particular things are identified by a general name. What is it about this particular object that gives us knowledge of its common shared species or knowledge of its kind? Why do we say this particular thing is a certain kind of thing?

To justify our assertion that this object is an X-kind of thing, and similar enough to other X-kind of things, we will have to refer to properties of the object itself. So in Aristotle’s view, we will have to refer to some common denominator in all objects of X-kind, or refer to at least one common fact about all X-kind of things. And we will have to find this common denominator in the particular things themselves. There has to be at least some real characteristic of an object which a)necessarily identifies the object as being an X-kind of thing, and b)is common to all X-kind of things.

To be a true example of X-concept or X-kind of thing, an object-P must have Y-essence. This has a double meaning. On the one hand, it means that the object must really have Y-essence, or that Y-essence must be found in the object. On the other hand, it means that Y-essence is logically necessary to X-concept, or we could say that Y-essence is in the definition of X-concept. Obviously though, this does not mean that the Y-essence in the definition of X-concept is a real substance --as though some substance were put into the definition. This is confusing language with reality, confusing concepts and substance. The Y-essence of object-P is a real property of object-P, not just a thought or an essence of definition. And the essence in the definition is Y-essence expressed in language, not Y-essence itself. The X-concept may include Y-essence, but this Y-essence is notational and referring to a real Y-essence.

The essence is that which is necessary and sufficient to the concept under which an object is identified and of which the object embodies. The expressing essence of a thing is thus significant to the concept of that thing. And a thing expresses or exemplifies a certain concept if, and only if, it possesses a certain definable essence. The essence has to be definable in order to be functional in language, but we should not get confused into thinking that the essence is just definitional simply because the essence is expressed in a definition. Just because an essence is definable in a definition of a general name, doesn’t necessarily prove that this essence has no real existence independent of definition. Here is where essentialist differ from nominalists. The essentialist, following Aristotle, will say that real or existing essences are apprehendable by the intellect via the senses, and then expressed in language by a general term that is then used in a class definition for the purpose of identifying things.

I know this thing in front of me is a cup, and not something else like a ball or a chair. But how do I know this is a cup? It is true that I must first know a proper definition or meaning of the general name ‘cup’, before I can know that this thing is a cup or properly called a cup. This definition might be expressed as something having a shape that can hold liquid and be functionally used for drinking. This eliminates a lot of things. But this definition might also be applicable to a bowl, for a bowl also can hold liquid and can also be used for drinking. I can hold a bowl of soup up to my lips and drink it, and my cat regularly drinks from a bowl. So maybe I need to add another necessary rule to the definition of a cup, like requiring that a cup must have the capacity to be grasped by one hand in a certain way different from how we can grasp a bowl. We could also stipulate that a cup’s primary function is for drinking liquids without other utensils and not for holding solid food that normally is brought to mouth by another utensil. This would generally distinguish cups from bowls, even though there may be a few rare examples producing overlapping confusions.

The main point, though, is that we not only need a definition of cups, a definition having essential rules, but we also need to empirically find in particular objects certain common and recurring characteristics, traits or ideal functions - which are possessed by all of the many different shapes of cups. That is, we have to find essential characteristics in or about the things themselves. Obviously, cups may look quite different and may be composed of different material. Yet in spite of these differences (which is what Aristotle means by accidents), there is at least ‘something’ similar or common to all of these things.

This ‘something’ may not be, and probably isn’t, an exact content of sensory information - such as the color, measurable shape, size or weight of the object. These are often the properties that differ in things of the same kind. But the essence-form of an object is more of an intelligible knowledge, gained by studying the common behavior and function of things, and it is not directly sensed (like particular color), yet it is still dependent on the senses. For example, the function of a cup is not an immediate content of the senses, and yet we could not recognize any such function without sensory knowledge of the shape, so even intelligible knowledge is tied to sensory knowledge. Also, the essence-form is stable and unchanging to the object, as long as it remains of a certain kind. And the essence-form is recurring and common in all objects of the same kind.

What is shown in the substance of a thing, or what is the [actual or potential] expression of a particular substance-thing, is the form. And that form, that [actual or potential] expression or characteristic, which is most significant can be called the essence of this thing. An essence is the substantial power or nature of a thing, what is brought forth and revealed by this substance-thing. The essence is what some thing is, in relation to other things, or what some thing has in common with other things recognized as similar. I go out and play with a ball. This is not the same thing as another ball I have, nor are the two balls similar in size and material; yet both are balls. How are both of these different things balls? They are both generally round, though maybe not perfectly round, and they both bounce, and they are both used for play. Because of these shared properties, both objects are playing balls. Of these properties, the roundness is the most significant to a thing being a ball. While all of these properties are certainly possible in regards to all balls, the roundness stands out as necessary to all balls because a ball, by definition, is spherically round or approximately so. Mostly what we mean by a ball is the playing kind of bouncy ball, but the word ‘ball’ in the most general sense could be applied to a ball of snow, which doesn’t exactly bounce, or maybe applied to a ball of fire, which we don’t often play with.

Anyway, I could say that this particular thing is round and bouncy, while this other particular thing also is round and bouncy. They both are round and bouncy things. So if someone asks what these things are, I could tell them that these things are round and bouncy, or that these are round and bouncy things. What these things are are round and bouncy. This ‘what’ is the essence-form (the essentia) --the power, quality or character of something that is most significant.

Also, the roundness and bounciness of these things are common and recurring in many other things. So if it is true that a thing is round and bouncy, the thing itself must really be round and bouncy. That is, if I assert that a thing is round and bouncy, then these predicates are true of this thing only if the thing really has round and bouncy essences (these real properties), and these essences may also be found common in other things that are truly round and bouncy.

Yet maybe one of my playing balls is slightly distorted in its roundness. This slight distortion is overlooked as a mere accident, so we still apprehend the object as round. Something doesn’t have to be perfectly round in order to be generally round. And maybe one of the balls doesn’t bounce as much as the other. This variance of bounce is insignificant to the property of general bounciness, for as long as a ball bounces at least somewhat it is generally bouncy.

The point here is that the general property, or essence, is not just identical to the specific observation or measurable information. The general is of a different logic all together and is not apprehended in the same manner as the specific knowledge. The general, universal essences -the roundness and bounciness - are intelligibly recognized in or from the specific sensory information. Yet the general-universal cannot be logically reduced to just sensory information, and thus it is regarded as existing, or expressing, independent of the specific.

If the existence of universal essences are regarded as independent of physical or particular existence, we have a Platonic view. If these existing universals are dependent on, but not identical to, particular existence, then we have an Aristotelian view. Though Aristotle could have held the view that universal recurring forms are what we apprehend about particular objects when we mentally strip away the accidental variances. In this sense, I will see both balls as ‘round’, having the very-same general roundness, once the imperfections are disregarded. And both will be recognized as ‘bouncy’, in the very-same way, once the variances of bounciness are levelised to a uniform essence of bounciness. The point is that if both objects have the same actual essence of bounciness, this bounciness has to be the same uniform quality, rather than two qualities of bounciness (low and high bounciness). So, it might well be that Aristotle regarded the knowledge of universal forms, or universals, as a kind of stripping away of the accidental imperfections or variances of things in order to apprehend these essences. He does seem to suggest that this inductive form of knowledge is a form of abstraction - abstracting away the unessential from the essential.