Real knowledge deals only with ideas; it is the perception of agreement or disagreement of these ideas. Yet, if we judge real knowledge only by comparing our ideas, then is there any necessary correspondence between our ideas and the world outside our minds or ideas? I think that Locke, as a realist, must seek some real correspondence between ideas and the world, because without this we would have obvious reasons for skepticism. Locke's solution is, I think, in his presupposition that simple ideas, as the basic building blocks of knowledge, are passively conveyed by simple sensations which are caused by real properties and powers of objects in the world. or Locke, we do have knowledge of real existences, that things or material realities do exist, so this reality transcends our ideas. Therefore, our knowledge of existences and the knowledge of ideas must agree, as well as just the connexion between ideas.
Simple ideas correspond to the real properties and powers of things because they are passively received. Berkley and other immaterialists might deny that there are such exterior things affecting the senses. Yet, even if we accept Locke's materialism and quality/power causative theory of sensation, all we can truly know is that the senses and simple ideas are affects of these properties and powers, and only because of these affects can we assume any correspondence. But what kind of correspondence this is, or to what extent it is reflective, is a difficult problem for which we have some reason for skepticism. If Y is caused by X, we can assume some correlation but we have no knowledge necessarily of X due to a knowledge of Y.
A number of objections can be raised against Locke's theory of ideas and
knowledge. First of all, how can we really know what is outside our
or ideas, if all that the mind can perceive are its ideas? The mind
perceive objects in the world, only ideas of objects in the world. All
the objects do is to affect the sensations and hence convey a
idea to the mind. There is a lot that can go astray in this meditation
Even if it all worked well most of the time, it is difficult to find a
to test the representational truth of these ideas, if all that we can
perceive and judge are our ideas.
Also, we might question what kind of
representation is being conveyed or produced? How does our
idea reflect the object at hand? Can mental ideas, or even sensory
physical properties in the world? Berkeley says that "ideas can only be
ideas". How can colors be like the powers producing them in the mind?
can size as known in the mind be like the real size of things?
Locke maintains that the secondary
qualities, such as color and sounds,
cannot be represented adequately by ideas but
the primary qualities, such as extension and shape, can. Yet, both
ideas are mental representations -- how do they then differ? The stone
not heavy and big in my mind, I only perceive that it is heavy and big.
is heavy and big to my mind? -- is it the same as the stone's heaviness
Somehow, ideas are always of a different sort than the physical
properties they assume to represent, so it is difficult to know how
ideas of primary
qualities could be any more adequate than secondary qualities, if both
are not exact copies. We can accept Locke's position on secondary
by acknowledging that objects do not give off color but only light
that is, color and other simply sensed qualities are
Berkeley of course accepts this, but he cannot see how
can assume that primary qualities are not mentally-dependent sensory
experiences as well. In other words, Berkeley cannot see how the
between qualities can be judged. For him, all experiences of qualities
in the same boat, that is, the mind. Once Locke or common sense admits
some ideas are not capable of adequately representing the real world,
because they are of a different mental category, then we have good
doubt that any ideas are adequate, since all ideas are of the same
category, and all objects being represented are hidden from perception
are only known by the senses.
Berkeley wonders how Locke can have certain knowledge of the distinction he has presumed. There is a veil of perception problem, in that the real world is hidden from the mind, though mediated by sensation and ideas. And there is a problem of sensory and conceptual representation, even if the real world was in fact influencing sensation and ideas. And if there were some properties adequately conveyed or copied in the mind, while some not, then there is a problem in knowing which are adequate or not.
A further problem criticized by Berkeley is Locke's knowledge of a
substratum or substance supporting the qualities of a given object.
There are two significant ideas here, one of substance and one of
materiality, and Berkley seems to assume that the two ideas are
necessarily linked for Locke. I think that Berkeley's assumption is
wrong. Locke's need for a substance is because the ideas of qualities
that appear to go together must presumably "belong to one thing", and
we cannot imagine how these ideas can subsist by themselves so we must
" suppose some substratum wherein they do subsist, and from which they
result, which we therefore call substance" (II 23,1).
Locke's need for substance, then, is a need for property instantiation. On the other hand, his need for materiality is fundamentally his need for their being a real world exterior or independent of our minds, that is, that there are real things in the world having real properties and powers. He calls this reality transcending the mind material, meaning that it is concrete and objective.
Locke admits that we can have "no clear idea of substance." Since there is no actual sensation or simple idea of such a substance or material substratum, then one might question how Locke arrived at such notions. Obviously, we can know nothing of substances, or the real nature of things, except the properties perceived. This is actually a different veil of perception problem than the one having to do with qualities. For not only are qualities not directly perceived, but the substance to which they belong is even veiled from any experience at all!
So, whereas [primary] properties can be adequately perceived or at least [secondarily] experienced, substance can only be inferred from experience. Locke, it seems, has made a kind of rational inference or supposition about that which he has no actual experience (or is this the one innate idea?), since all that he can actually experience are properties and powers of objects, not property-less substances. One might be then inclined to say of Locke that he was not a pure empiricist because he made inferences and rational assumptions. Yet, this claim, which I think Berkeley hints at, would not be right of Locke, because Locke's empiricism does not reject inferences or abstractions, but only requires that ideas should come from the building blocks of experience.
Substance is necessary in Locke's system because his real properties need substantiation, that is, there must be something real to which real properties refer. There must be a subject (or in this case object) in any statement describing properties or claiming to be true. There must be a `this' or `what' is... such. The substance in which qualities are contained, or to which properties refer, does not even need to be physical. We could say, although Locke does not, that all qualities are physical, all ideas are mental, and all `things in themselves' or substances are spiritual, spirits, or non-physical/mental. Whatever the terms used, they have their meaning only in relation to each other Thus, Locke's substance does not need to be `physical'; in fact, what we know of substance is that `it' is of a different sort than just properties or just ideas.
Berkeley questions the intelligibility of the idea of matter, because we only have empirical knowledge about and from experience, and the only reality we have experience of are sensible or imagined ideas. Matter may be an imagined idea (though Berkeley has trouble with this too) but not sensible. We cannot sense matter, or any such substratum, because all that we can have sensible ideas of are properties of so-called `things'.
The general idea of substance is derived at from abstraction, one of the mind's abilities in producing complex ideas and knowledge. Locke's abstractions are always derived from experience of particulars, and it is a kind of subtraction or an elimination of accidental properties. It is a re-simplifying of the complex. General ideas, such as human being or automobile, are found by noticing that certain properties go together in some things and if we then eliminate the properties from these similar `things', we know that all such things have those properties. His abstraction of substance is a perception that all things have some properties, so what substance is a that which has properties. The idea we have of this substance through a process of abstraction is the nominal essence, while the real nature of that which has properties is the real essence.
For Berkeley, all that can exist are what is perceived or the perceivers perceiving. The only objects existing are those objects perceived, and these objects are sensible ideas or objects of the mind. Thus, all `objects' are mind-dependent; they are sensations of the mind. Berkeley argues that sensations or ideas of objects cannot exist without the mind, so there can be no certainty of objects existing independently. All that we know are our sensations.
Unseen colors and unsmelled odors cannot exist without a mind perceiving them. Since color is an experience in the mind, it cannot exist without the perceiver. Locke would agree that ideas of objects are mind-dependent, but the objects themselves, and the qualities of those objects, are independently real beyond the mind. It is possible, in spite of Berkeley's skepticism, that real material properties and powers could exist without the mind perceiving them. Thus, Berkeley's arguments do not necessarily eliminate Locke's inference. The object perceived [in the world] can be independent of the perceived object [in the mind].
We never perceive objects directly, only ideas, so we can never know of any correspondence between our ideas and the supposed objects represented. Since we cannot directly perceive the object, we cannot use `this' in a comparison with the idea of `it'.
We cannot even know if the objects are even out-there,
or material, or real in
the manner of having powers affecting our mind's eye. For Berkeley, all
that we have at-hand are our ideas. Granted, these ideas are most often
or about `things', still, we have no knowledge of these things and we
even know if these `things' are really existing. Yet now, we might
how, for Berkeley, are his ideas substantiated? What makes the
between ideas and what ideas are `of' (only ideas) or to what do these
conform. For Berkeley this is God's Will or Intention. Ideas in
do make for reality, but God-given ideas are the reality, as well as the
spirits perceiving them. In this way, ideas come from an archetypal
with God as the ultimate Perceiver and Active Dispenser of ideas.
Hallucination is possible in Berkeley's world, illusion and delusion are
realities of the imagination but mis-representations of God's ideas
So, it is possible to be wrong; it is possible to mis-perceive. Or is
mis-perception really God's Will? Berkeley is not much a theologian at
I assume that Berkeley maintains some distinction between real
and non-real, or even in pragmatic terms, a distinction between useful
ideas and non-useful. Either way, a distinction or judgment is
a choice, a decision between right and wrong, good or bad, useful or
And how could this be avoided? Berkeley is still in the same problem as
Locke. Both need to make an adequate correspondence between the idea
perceived by perceivers and what is real, in the sense of having an
independent reality not dependent upon the perceiver or perception. For
Locke this is what he calls material, having independent
substances and properties
powers affecting other substances and properties and the senses
of perceivers. For Berkeley, this reality is God's Mind. What makes this
independently real is that God perceives the idea in His eternal
that God wills that certain ideas be made known to the senses, although
is possible that perceivers might mis-apprehend the ideas evoked from
The moral or path for both Locke and Berkeley must then be rightness or true correspondence between the idea and its true idea or property-substantiation. Truth is in the correspondence between X and Y, or in that X is Y, or that the idea or property Y is what X is, or that Y is a property of X. In Locke there is a question of how his idea Y can be compared with a reality X which cannot be known except by his idea Y. In Berkeley there is a question of how his idea Y can be compared with true sensations X of the intended world of God's creation, intended ideas which cannot be known except by his idea Y. Berkeley, thus, ends up in an equally skeptical position as Locke. It's unavoidable.
Berkeley also objects that we cannot even know if objects of our mind
represent something out there beyond it. He wonders if objects are
out there at all, that is, apart from the mind. Corollary with this is
skepticism of there being a material reality to those objects sensed,
sensible ideas. To know that objects are really out there independent
mind is to know what is beyond the mind and this is impossible and
inconceivable. The mind cannot perceive beyond itself or know other than
the ideas it holds. Thus, the material world, or any world independent
the mind, is but a supposition not based upon actual experience. But the
most that Berkeley can really say is that the material world
mind cannot be proven because it is beyond the veil of perception.
For a realist, this is not an adequate argument for immaterialism, since immaterial ism can neither be proved, and all that has been done is the casting of a shadow of doubt upon realism. Granted, Berkeley, the world of our sensory experience could possibly be a projection of God's ideas into our minds. Or maybe the world could be something only in the mind of God -- so what, so how does this mean that the world is not `material' if by `material' we can only mean the true and most vividly real? And for Berkeley there is still `something' independent of perceivers or the mind: that is God (true essence/reality/substance) and God's ideas (true properties or true sensible ideas).
Once Locke makes a distinction between primary and
secondary qualities, and then admits that the secondary qualities
experienced in the mind do
adequately match the reality of objects; he has left himself open to
criticisms from Berkeley. First, primary and secondary qualities cannot
distinguished or separated from each other, because they are necessarily
Second, the primary qualities
cannot be known any better than secondary qualities, because both are
mind-dependent and can vary according to the perceiver.
Berkeley argues that one cannot make a distinction between primary and
secondary qualities. Each are experienced as bound up with each other
I perceive a tree, for instance, I have awareness of the
extension, the shape, the color,
and possibly the smell. Berkeley would argue that I do not perceive
these qualities separately and then put them together in the idea of
`tree'. The perception of the tree is a whole idea [of `tree']. For
Berkeley, we perceive the tree as it truly is, that is, as it exists as
whole idea of `tree'. The idea is what is perceived, and the idea is all
that there is. So, in perceiving the tree all of the qualities sensed
necessarily go together. If it did not have the shape of a tree, then it
would not be known as a tree, and if it did not have the color of a
would not be known as a tree. Shape and color necessarily go together
sensible idea of `tree'. And this applies to all sensible objects.
For Berkeley, extension is bound up with color, solidity with touch, and size with viewpoint. I can agree with Berkeley that in our experience of things the different qualities, primary and secondary, appear to be bound together with that thing. But this is not the same as declaring that the qualities cannot be separated from each other, or that the object's qualities cannot be analyses separately. Granted, a certain tree is only that tree when if it has a certain kind of shape and color. But, I can perceive the color separately from the shape, and vice versa. Also, different senses tell me different things about the tree. The tangible shape is different than the visible shape. I cannot touch the sighted and cannot sight the touched.
Next, Berkeley argues that primary cannot be known any better than secondary Q. And yet, we have the possibility of measuring primary qualities under neutral circumstances. In fact, we have the possibility of measuring any intrinsic properties or powers of objects Thus, we can measure both primary and secondary qualities; but we cannot necessarily correlate the ideas of secondary qualities with the powers producing those sensory experiences. It is this difference, and only this difference, which Locke should have to defend.
Locke must infer that material reality exists and the properties/powers of it. This inference comes out of experience but it is not directly the result of experience. In other words, Locke's realism depends upon some mental operation at least once removed from actual sensory experience. Berkeley uses this to argue that Locke's ideas of these material properties and powers are mind-dependent, to which Locke would agree. But Berkeley concludes from this that nothing could then exist without the mind, which is an unsound assumption. Because for Locke, knowledge and ideas are mind-dependent, they require a perceiver and mind, but there is reason to infer from this that these ideas are derived from independent realities and powers outside the mind and that perceptions are about real things existing without the mind.
In Berkeley's view, sensible objects are actually complex ideas given
and perceived directly by sensation. Berkeley perceives
the tree as tree, whereas
Locke perceives but an idea of the tree - which is not the same as the
but an inferior representation of it. The real tree
is hidden from view, but for
Berkeley the real tree is the idea of it. How then, can Berkeley know
is mis perceiving or not? Berkeley would probably counter that this
is even worse for Locke. Berkeley's `real world' is a world of
sensible ideas. The objects of the senses are nothing but ideas. Thus,
ideas of objects are what they are: Idea=Reality. Reality is
and non-material (though "non-material" is meaningless here since this
reality appears in the same manner as the materialist's reality).
distinct in Berkeley's system is that reality is mind-dependent. But it
not dependent upon any mind: only the mind of God. So what is the real
difference between this and the realist view, except that Berkeley's
is in the mind of God and in the world that God creates for us. Still,
is a world. Still, there is a reality independent of our individual
Still, there are somethings and events of which we are confronted, of
appears to affect us and to which it appears that we can affect it. The
phenomena we live within is the same for both Locke and Berkeley; all
is really different is what they call it and to what they infer produces
it. The two opposing metaphysics do not seem to be opposed in their
application or practice of living. So what does the difference really
matter, or non-matter? Maybe one difference is in the practice of
Locke would look for causative powers within the objects perceived. Berkeley would not look for these causes, but instead might look for some regularity of relations between the ideas-objects perceived in order to predict God's Command. This difference may not be all that great, though, because Locke might just as well look at the regularity of relations between objects (as understood in the mind), while Berkeley might just as well find that certain events tend to be preceded by other certain events and thus build some theory of God's causally-connected Reasoning in order to predict further events. Of course Berkeley might wonder if God might invent or perceive ideas which do not make for regularity or produce what we call miracles; and yet Locke as well might wonder about the mystery of nature or perceive events surprising to casual theories or be unable to predict nature. And Locke is, in line with his common sense, assuming that nature works in regular, lawful, predictable (as distinct from predicted) ways; just as Berkeley, in line with his common sense, is assuming that God works in regular, lawful, predictable ways.
Yet for Berkley, my idea may not represent reality or truth if it does not actually conform to the divine or original idea as perceived by God.
The idea of God is proven by Berkeley by steps of reason and not direct experience. Just as Locke had to infer actual substance and material powers in the world, Berkeley had to reason an ultimate essence having power in the world and in our minds. He reasons that since ideas require at least some perceiver, that they cannot exist without some mind perceiving them, and I must know that the world of my experience, my sensible ideas, do not depend upon my agreement or not, that I do not create this sensible world, but that I am often a victim of it's givenness; then we must conclude there to exist a Greater Mind as continuous perceiver and cause of these ideas. Berkeley assumes this to be the One God, but from his reasoning there might be many Gods, just as long as they perceive and cause the ideas of this given world.
There is a distinction, for Berkeley, between ideas of the imagination and ideas of the senses. Ideas of the senses are really real, whereas ideas of the imagination are often fancies of what is real, although much of knowledge is of the imagination instead of the senses -- the capabilities of thinking, as defined by Locke, are accepted by Berkeley as means to knowledge, except abstraction.
the ideas of the imagination in dreams and hallucinations are less real because they are less vivid, less orderly and more fragmented. This is Berkeley's epistemological test of the real. But, in dreams my sensory ideas are very vivid and appear to be real, at least to the point that it "fools" me; so is this an adequate test? I think not. And the world often appears dis-ordered and fragmentary, at least it has to me! But the test could be what is most regular and continuous in my experience and in what way do I affect the world (I don't affect the world very much in my sleep, and I can easily make a distinction between going to sleep and waking up).
Berkeley accepts the [Locke's]
mind's ability to compound, divide, compare and relate,
but not to
abstract. We can have general ideas, or general words, "being made to
represent or stand for all particular ideas of the same sort" (P 12).
how do I know `what is' "of the same sort" without first having some
idea? The general idea, for Berkeley, is like a concrete imagined
of many [similar] ideas.