abstract ideas. The former
comprehend the whole world of experience; the latter are concepts, and
are possessed by man alone amongst all creatures on earth; and the
capacity for these, distinguishing him from the lower animals, is called
reason.

Time and space can each be mentally presented separately from matter,
but matter cannot be thought of apart from time and space. The
combination of time and space in connection with matter constitutes
action, that is, causation. The law of causation arises from change,
that is from the fact that at the same part of space there is now one
thing and then another, and this succession must be the result of some
law of causality, seeing that there must be a determined part of space
and a determined part of space for the change. Causality thus combines
space with time.

Much vain controversy has arisen concerning the reality of the external
universe, owing to the fallacious notion that because perception arises
through the knowledge of causality, the relation of subject and object
is that of cause and effect. For this relation only subsists between
objects, that is between the immediate object and objects known
indirectly. The object always pre-supposes the subject, and so there can
be between those two no relation of reason and consequent. Therefore the
controversy between realistic dogmatism and doctrinal scepticism is
foolish. The former seeks to separate object and idea as cause and
effect, whereas these two are really one; the latter supposes that in
the idea we have only the effect, never the cause, and never know the
real being, but merely its action. The correction of both these
fallacies is the same, that object and idea are identical.

One of the most pressing of questions is, how certainty is to be
reached, how judgments are to be established, and wherein knowledge and
science consist. Reason is feminine in nature; it can only give after it
has received. Of Itself it possesses only the empty forms of its
operation. Knowledge is the result of reason, so that we cannot
accurately say that the lower animals know anything, but only that they
apprehend through the faculty of perception.

The greatest value of knowledge is that it can be communicated and
retained. This makes it inestimably important for practice. Rational or
abstract knowledge is that knowledge which is peculiar to the reason as
distinguished from the understanding. The use of reason is that it
substitutes