idealists, and led him to deny the existence of outside objects, and
hold that existence or reality meant being perceived and nothing more.
But if we take Berkeley's position, it becomes very difficult to say
what we mean by judgments being true. If things only exist as we think
of them, or perceive them, or rather if they are only our thinking of or
perceiving them, the question of the truth or falsity of our statements
about them cannot arise.
This idealism Kant is careful to refute, and he points out that there is
no evidence for its fundamental proposition that we know our mind more
directly than we know objects. We are only conscious of ourselves in
knowing something not ourselves. We do not invent the notion of
externality or outsideness in space from an experience in which it
originally has no part. Externality is implied in our most simple
experience. We begin with consciousness of outside things, and only
become conscious of our own mental states or processes later. But it is
important to observe that, the truth or falsity of subjective idealism
has no bearing whatsoever on the question with which Kant was concerned.
If I ask how I can lay down rules about what I have not yet experienced,
I am not in the least helped by being told that I only experience what
is in my mind. For the question will equally arise, How do I know what
is going to be in my mind? The question idealism ordinarily discusses,
as to whether the objects of our awareness are in our mind or outside,
are in their nature mental and dependent on the mind or not, is entirely
and absolutely irrelevant to Kant's purposes.
But it is a fact, and one that has got to be explained that in judgment
we go beyond what is present to our minds, and that, in so anticipating
what we shall experience, we assume that certain principles hold of all
that has been or may be present. With that difficulty idealism, as
ordinarily understood, has nothing to do. Representationism tried to
give some account of this going beyond what is present to our minds by
suggesting that truth is a reference from ideas to reality; but, as we
saw, if we know only ideas, such a reference is impossible. The
doctrines opposed to representationism, that only ideas exist, or that
we directly know real objects, allow the existence of nothing contrasted
with what we are apprehending to which a reference in judgment can be
made. No one who is satisfied with any of these positions can have seen
Kant's problem.
If Kant then, is not a subjective idealist what does he mean by saying,
as he constantly does, that we only know phenomena, and why should that
limitation of knowledge help him in any of his difficulties? He means,
in the first place, that all knowledge depends upon perception. The
first paragraph of the first part of the _Critique of Pure Reason_ makes
that clear. "Whatever the process and the means may be by which
knowledge reaches its objects, there is one that reaches them directly
and forms the ultimate material of all thought, viz. perception. This
is possible only when the object is given, and the object can be given
only (to human beings, at least) through a certain affection of the
mind."
Now, although we perceive an objective reality, sense perception
obviously gives a very imperfect knowledge of objects. We see only some
sides and aspects of things, and not others. What we see depends on
changes in our position. Further, we know that what we see is only a
small part of the nature of anything. We think of reality as an
interconnected system, but we only perceive a very small part of it, and
what we perceive depends upon the particular time and the particular
part of space in which we live. In our experience we are never really
content simply with what we perceive; we perceive much too little for
that. We are always inferring from what we see to something beyond it.
What is that something beyond, which, as we have seen, is implied in all
judgment? We might hold that it was the things as they really are as
distinguished from things as they appear, or phenomena, and that, when
we turned from perception to thought, we turned from illusion to
reality. Kant denied this. He held that, if you examine a scientific
judgment about anything you perceive, such as that yellow thing is gold,
you will find that, if you know what the judgment means, you will be
able to say: Then, under such-and-such conditions--if you weigh it, for
example--you will have such-and-such a perception. The appeal is not
from what you perceive to what you think, but from what you perceive now
to what you will perceive under such-and-such conditions. Such a
reference indeed, implies thought and what is ordinarily called a
concept; but our knowledge of concepts used in science always means
that, if we know what is meant _e.g._ by calling anything gold, we know
how it will behave under such-and-such conditions. The concept, in
Kant's words, is a function of unity in our representations. The task
of thought, then, is not to turn the mind away from what we perceive,
but to help us to transcend some of the limitations of our perceptions,
or, to speak more accurately, to set somewhat further back the limits of
our perception; for thought never entirely transcends these limits. Our
knowledge is always conditioned by the fact that we are finite minds
living in a particular place and at a particular time; but thought can
extend the range of our perception in space and in time.
The limitations of our perception have, for Kant, a double aspect, which
determines his division of the first part of the _Critique_ into two
parts--the _AEsthetic_ and the _Analytic_. In the first place, our
direct knowledge of space at any one time is always knowledge only of a
part of space; our direct knowledge of time, whether in present
consciousness or in memory of our own experience, is knowledge of only a
part of time; and the things in the space we directly perceive, or in
the time we experience, are what they are by their relation to space
outside the space we see, and time beyond the time we experience, and
that limited space and time we treat, therefore, as parts of one
all-embracing space and one all-embracing time, and in the conception of
an indefinitely extended space and time we can think of the space in
which all things exist, and the time in which all things occur, of which
we only see and experience a small part. The science of astronomy
obviously talks of space and time far beyond anything we could ever
perceive, but we go beyond such direct perception in such simple
expressions as "forty miles from here" or "three days hence." And, when
Kant says that space and time are only phenomenal, he does not mean that
they are mental, but that we only know them through perception, and that
we get at absolute space and time not by going from what we perceive to
what we think, but by thinking of what we perceive indefinitely
extended. All definite statements about space must come back in the end
to "so far from _here_," all about time to "so long from _now_," and the
fact that all our knowledge of space and time is got by adding to or
extending in thought the space and time we directly perceive does,
according to Kant, solve some obstinate puzzles about the nature of
space and time.
In the second place, if we consider our knowledge of objects, we realise
that, as we said, at any one moment we only perceive them in part or
from one position. What we directly perceive of them is fragmentary and
discontinuous, one aspect seen now, and another aspect seen at another
time. But we do not think of the things as existing in that
discontinuous way; we think of them as having a nature of their own.
That does not contradict, but is something very much more than, what we
perceive, and our knowledge of any object is got by piecing together the
aspects we directly perceive; but that piecing together, or synthesis,
is not haphazard. It is governed by rules--rules partly derived from
the nature of the particular thing we are concerned with, and partly
more general rules, which come from the relation of this work of piecing
together to the framework of space and time by help of which it is done.
Kant's conception of knowledge, then, is something like this. Each of
us is in direct contact with reality, but we perceive directly only a
small part of it, and, as our consciousness moves on in time, and as we
change our position in space, we are directly conscious of different
small portions of reality. A part of the whole is illumined by direct
perception, but the whole stretches beyond that indefinitely in space
and time. In the part we directly perceive there is a temporal order
and a spatial order. Things are given to us arranged in space and
ordered in time, and these arrangements or orders in the space and time
that is directly given to us in perception have certain rules, and we
think of these principles of arrangement as extending indefinitely
beyond the space and time given to us in perception. When we make
judgments about reality beyond our perception, we think of things as so
arranged in the space and time beyond our perception as we should see
them arranged were the range of our perception sufficiently wide.
Further, it is most important to remember that we do not remain in one
place and at one time and make guesses of what may happen in the
darkness beyond. Though our perception at any one moment is limited, we
can connect what we see at one time with what we see at another. We
can, by means of language and writing, use the perception of others to
fill out our experience, until gradually our scientific judgments, our
knowledge of what we should perceive under all sorts of possible
experience, seems to bulk much more largely than could our individual
perceptions. But we are still, Kant would say, getting at our knowledge
of what is beyond by piecing together what we and other people have
perceived, and the whole is always much more than that.
What, then, is meant by the contention that we can know things in
themselves which Kant is earnest to refute? It might mean that we do in
perception attain to a complete knowledge, but that would be obviously
untrue. As Kant understood the claim, it meant rather something like
this: In thought we are obviously not limited by our perception. We are
always assuming certain principles, such as the laws of space or the
principle of causation, to hold of all reality, both what we do and what
we do not directly perceive. May we not say, then, that these
principles hold of all reality, and argue from that fact to what the
nature of the whole must be? If everything that we know is caused,
_e.g._, may we not apply the principle of causation to all reality and
say that it must have a cause?
When we come to consider the _Dialectic_, the second main division of
the first _Critique_, we shall notice Kant's detailed analysis of these
arguments, and how he points out that you can in this way get
contradictory results. In the meantime it must be observed that in these
arguments we start from principles applied to what we perceive and
expressing connections between the different things we perceive, and
then apply them beyond everything we do or could perceive. That means
that we imagine that we can take these principles out of relation not
only to this or that detail of perception, but out of relation to any
perception at all, and thus apprehend reality by thought independently
of perception.
Kant's answer is that thought cannot directly apprehend the nature of
the whole, and these universal principles, such as the principle of
causation, are only principles by which we connect one perception with
another to amend the discontinuous and fragmentary nature of our
perception; they are rules for the synthesis of what we perceive. By so
synthesising our perceptions we come to a less imperfect knowledge of
the whole, but apart from perceptions the principles have no meaning at
all.
Kant's idealism, _i.e._ his insistence that we know only phenomena, not
things in themselves, is relevant to his problem, because it implies the
denial of the view that thought has objects apprehended independently of
perception, and because it insists that we can only know directly what
we perceive, or things as they appear to us, that in our process from
perception to knowledge we start with what is present to our perception
and end with what is or with what might be present to our perception,
and that this process is possible by reason of our continued
consciousness in time. The process, Kant holds, is governed by certain
principles. These depend upon the part played by space and time in all
our perception, and the manner in which we employ space and time in
piecing together our discontinuous perceptions.
Now, obviously it is quite possible to hold this position without having
thought out what is implied in being present to the mind in perception.
This is what Kant did. He describes perception in different and
inconsistent ways. The reason for this inconsistency is that Kant is
not concerned with the nature of perception, but with the relation of
what is immediately perceived to what is not but may be immediately
perceived, and he therefore never worked out any consistent account of
perception. He sometimes talks of perception reaching objects directly,
and refutes the view that we perceive only what is in our mind. (This,
indeed, is implied in his distinction of space and time as forms of
_external_ and _internal_ sense respectively.) But usually he takes the
ordinary idealist view that we do not perceive things, but affections
produced in us by things. Owing to this inconsistency Kant constantly
seems to be stating very much more than he has any right to. This is
especially true in all that he says about knowledge being confined to
phenomena and not extending to things in themselves. When he talks of
our knowing only phenomena, he sometimes seems to mean that we know
objects, things in themselves, only in part, in so far as they appear to
us. That would make the distinction between the phenomenon and the
thing in itself a distinction between the same thing imperfectly and
perfectly understood. He sometimes, and this is his more usual view,
seems to mean that we are aware of appearances, entities separate and
distinguishable from the objects which produce them in our minds. But
if we work out in any of Kant's arguments the point of his appeal to the
fact that knowledge is only of phenomena, we shall find that in every
case the difference between a subjective idealist and a realist view of
perception, of what "being present to the mind" means, is irrelevant,
and that his argument holds on either theory.
We must now turn to Kant's account of space and time which is given in
the _AEsthetic_, the first part of the _Critique_. He begins by showing
the impossibility of the two views of the nature of space and time which
then held the field, the views of Newton and Leibniz. Newton had thought
of space and time as realities, things in themselves existing along with
other things. But obviously we cannot think of space as a separate thing
existing by itself; for space without things would have no determination
or possibility of determination, and would be to us just nothing,
whereas, as it is, it is something to us. The same holds of time. The
Newtonian doctrine, Kant says, "forces us to assume two eternal,
infinite, and self-subsisting non-realities, which are there, without
any reality in them, only that they may comprehend all reality." Just
because things are in space and time, space and time are not themselves
things. But if this makes us say that space and time are only relations
between or qualities of things, we find ourselves in difficulties as
obvious. We do not come to apprehend space and time by comparing things
and seeing that they have a common quality of being "spatial" or
"temporal," as we come to apprehend redness, _e.g._, by seeing red
things. The perception of space and time is implied in each and every
perception of things. We cannot, therefore, derive them from our study
of things; we must begin with them. Further, Kant notices, as against
Leibniz, that space and time are not ordinary concepts because they have
no instances. Different men are instances of man, but different spaces
or times are only parts or determinations of the one space and the one
time. As against the view, then, that would make space and time only
relations, derived from our comparison of things which are not temporal
or spatial, Kant insists that space and time are a priori. We cannot
see things without seeing them outside one another--_i.e._ in space--or
experience succession or change without experiencing it in time. Space
and time, then, have a certain independence of things in space and time.
The qualitative differences of things in space or events in time do not
affect the nature of space and time, and we can and do study and discuss
spatial and temporal relations quite independently of such differences.
Space and time, then, can be abstracted from things in space and time.
Yet, on the other hand, we cannot think that space and time exist
independently of things. They do not exist in abstraction; for, though
the specific differences of things in space and time are irrelevant to
the nature of space and time, if there were no things, or if there were
no differences, there could be no space and time as we know them. "The
empirical perception," says Kant, "is not compounded of phenomena and
space, of the sensation and the empty perception." Space and time,
therefore, Kant says, are not things in themselves.
What, then, are they? Kant's answer is that they are forms of our
perception. Space is the form of external perception, and time is the
form of internal perception, and Kant holds that by this answer we can
understand both how our knowledge of space and time may be a priori, how
spatial and temporal distinctions may be abstracted from the differences
of things, and how we may avoid the difficulties consequent on regarding
time and space as independent things.
What, then, does Kant mean by _form_? He seems to mean two things,
which he does not clearly distinguish. The first meaning is best
described in his own words: "In the phenomenon I call what corresponds
to the sensation the matter of the phenomenon, and that which causes
that the manifold of the phenomenon is perceived as arranged in specific
relations I call the form of the phenomenon." We are here face to face
with the ultimate difference of form and matter, or order and that which
is ordered. When Kant calls time and space the form of our perception
he is simply calling attention to the fact that in all that we perceive
we find this distinction. It is something found, given, not made by us.
By the word "form" Kant does not mean anything specially subjective as
contrasted with matter or content, for he carefully distinguishes
between space and time, and such qualities as colour, which get their
nature in part, he thinks, from the specific nature of the sense organ.
Compared with such qualities space and time are objective. The phrase
"forms of our perception," then, does not really explain anything about
space and time; it only emphasises the fact that the distinction between
space and time and objects in them is found in what we perceive, and
that there is no meaning in discussing either side of the distinction as
though it were quite independent of what we perceive.
But form has also another meaning which justifies Kant in calling space
and time _only_ forms of our perception, and hence subjective. For,
while these forms are _found_ in what we perceive, the distinctive part
which they play in our knowledge is due to the fact that we use space
and time as a framework by which to connect our scattered experiences.
We come to think of the space and time we perceive as parts of an
absolute space and an absolute time. We perceive parts of space and
time, but absolute space and absolute time we do not perceive. They are
the form we perceive imagined indefinitely extended. We order the
particular parts of space and time which we do perceive in reference to
absolute space and time. Yet absolute space and time are only known
through the finite parts of space and time which we actually experience.
Hence absolute space and time are not perceived realities or perceived
orders, but ways in which we organise and arrange what we perceive.
Now, the qualities of space and time which are hard to think of as the
qualities of a thing that exists, _i.e._ their infinite divisibility and
infinite extension, are qualities of absolute space and time. When we
say that space is infinitely divisible, we do not mean that any existing
thing is made up of an infinite number of parts. The divisibility of
space and the divisibility of matter are quite different. An inch as a
spatial determination is infinitely divisible, but the divisibility of
the actual stuff which any inch may measure is a matter of empirical
investigation, and ought to admit of a definite answer. That means
that, while we use determinations of space which we consider infinitely
divisible and infinitely extensible to measure things in space, we do
not consider that these determinations, fractions, or multiples of
inches or centimetres, have anything to do with the constitution of the
thing they measure. It was not put together in fractions of inches.
Thus we must distinguish between space as the form of what we perceive,
the next-each-otherness of things, and the use we make of that form to
construct by means of measurement order in all different perception.
The first is obviously the form only of what we perceive, and gives rise
to no transcendental questions. But the second, infinite space, though
it seems to transcend our perception, has still only meaning in
reference to perception, is only a way of ordering our perceptions. The
same holds good of time.
We can see now what Kant means by saying that time and space are
empirically real and transcendentally ideal. Kant does not maintain
that space and time are illusions. They are a constant element of what
is given us in perception. It is only when we try and go beyond our
perceptions, and take space and time as things existing independently of
what we perceive, thus trying to transcend the limits of possible
perception, that we fall into illusion. Space and time have meaning
only as elements in what we perceive, or in connecting what we perceive
now with what we may perceive.
*CHAPTER IV*
*THE CATEGORIES AND THE PRINCIPLES OF PURE UNDERSTANDING*
Kant makes the distinction between perception and understanding depend
upon the distinction between the receptivity and the spontaneity of the
mind. In the _AEsthetic_ he has been concerned with time and space as
elements in what seems to be given to the mind. Before we begin to ask
the questions of science, before we analyse, describe, or classify,
before we have to think, we perceive. Time and space are not got at by
thinking or generalisation. For before we can say anything about any
part of our experience, it is _given_ us in a certain spatial and
temporal order. If we open our eyes at any moment, we are, without any
conscious effort of thought on our part, confronted with an elaborate
content. It seems simple to distinguish this receptive attitude of the
mind in perception from its activity in thinking.
The distinction is not really so simple as it appears. For we all know
that what we perceive depends, at least to some extent, on the mind's
activity. We are familiar with the reflection that men see what they
want to see or what they are looking for. This is clearly shown in the
case of hearing by the difference in what we hear when we are listening
to a language we understand and when we are listening to an unfamiliar
language, or in the common experience when, after failing to hear what
someone has said, we think what it must have been, and then seem to
recall the sound, not as we heard it, but as we should have heard it if
we had heard it rightly. Anyone who reflects on the process of fast
reading will realise that we do not perceive or notice all the letters
on a page; we fill in from our imagination, as we discover when we read
words that are not on the page. It is a very hard thing, giving up all
interpretation and inference, to describe faithfully just what is there
to see.