OF THE IDEA OF TIME.
1. RESPECTING the Idea of Time, we may make several of the
same remarks which we made concerning the idea of space, in
order to show that it is not borrowed from experience, but
is a bond of connexion among the impressions of sense,
derived from a peculiar activity of the mind, and forming a
foundation both of our experience and of our speculative
knowledge.
Time is not a notion obtained by experience. Experience,
that is, the impressions of sense and our consciousness of
our thoughts, gives us various perceptions; and different
successive perceptions considered together exemplify the
notion of change. But this very connexion of different
perceptions,--this successiveness,--presupposes that the
perceptions exist _in time_. That things happen either
together, or one after the other, is intelligible only by
assuming time as the condition under which they are
presented to us.
Thus time is a necessary condition in the presentation of
all occurrences to our minds. We cannot conceive this
condition to be taken away. We can conceive time to go on
while nothing happens in it; but we cannot conceive anything
to happen while time does not go on.
It is clear from this that time is not an impression derived
from experience, in the same manner in which we derive from
experience our information concerning the objects which
exist, and the occurrences which take place in time. The
objects of experience can easily be conceived to be, or not
to be:--to be absent as well as present. Time always is, and
always is {132} present, and even in our thoughts we cannot
form the contrary supposition.
2. Thus time is something distinct from the _matter_ or
substance of our experience, and may be considered as a
necessary _form_ which that matter (the experience of
change) must assume, in order to be an object of
contemplation to the mind. Time is one of the necessary
conditions under which we apprehend the information which
our senses and consciousness give us. By considering time as
a form which belongs to our power of apprehending
occurrences and changes, and under which alone all such
experience can be accepted by the mind, we explain the
necessity, which we find to exist, of conceiving all such
changes as happening in time; and we thus see that time is
not a property perceived as existing in objects, or as
conveyed to us by our senses; but a condition impressed upon
our knowledge by the constitution of the mind itself;
involving an act of thought as well as an impression of sense.
3. We showed that space is an idea of the mind, or form of
our perceiving power, independent of experience, by pointing
out that we possess necessary and universal truths
concerning the relations of space, which could never be
given by means of experience; but of which the necessity is
readily conceivable, if we suppose them to have for their
basis the constitution of the mind. There exist also
respecting number, many truths absolutely necessary,
entirely independent of experience and anterior to it; and
so far as the conception of number depends upon the idea of
time, the same argument might be used to show that the idea
of time is not derived from experience, but is a result of
the native activity of the mind: but we shall defer all
views of this kind till we come to the consideration of Number.
4. Some persons have supposed that we obtain the notion of
time from the perception of motion. But it is clear that the
perception of motion, that is, change of place, presupposes
the conception of time, and is not capable of being
presented to the mind in any other {133} way. If we
contemplate the same body as being in different places at
different times, and connect these observations, we have the
conception of motion, which thus presupposes the necessary
conditions that existence in time implies. And thus we see
that it is possible there should be necessary truths
concerning all Motion, and consequently, concerning those
motions which are the objects of experience; but that the
source of this necessity is the Ideas of Time and Space,
which, being universal conditions of knowledge residing in
the mind, afford a foundation for necessary truths.
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