n of
a quantity. This thought is the thought of number, and since
by it we present to ourselves an instance of a quantity, it
is the schema of quantity.' But if this be its drift,
considerations of sense demand that it should be rewritten,
at least to the following extent: 'If we are to present to
ourselves an instance of a _particular_ quantity [which will
really be a particular number, for it must be regarded as
discrete, (cf. B. 212, M. 128 fin., 129 init.)] e. g. three,
we must successively combine units until they form _that_
quantity. This process involves the thought of a successive
process, by which we add units according to the conception of
_that_ quantity. This thought is the thought of a particular
number, and since by it we present to ourselves an instance
of _that_ quantity, this thought is the schema of _that_
quantity.' If this rewriting be admitted to be necessary, it
must be allowed that Kant has confused (_a_) the thoughts of
particular quantities and of particular numbers with those of
quantity and of number in general respectively, (_b_) the
thought of a particular quantity with that of a particular
number (for the process referred to presupposes that the
particular quantity taken is known to consist of a number of
equal units) and (_c_) the thought of counting with that of
number.

[13] This statement is, of course, not meant as a definition
of counting, but as a means of bringing out the distinction
between a process of counting and a number.

[14] For the thought of a number is the thought of a quantity
of a special kind, viz. of a quantity made up of a number of
similar units without remainder.

The account of the schema of reality, the second category, runs as
follows: "Reality is in the pure conception of the understanding that
which corresponds to a sensation in general, that therefore of which
the conception in itself indicates a being (in time), while negation
is that of which the conception indicates a not being (in time). Their
opposition, therefore, arises in the distinction between one and the
same time as filled or empty. Since time is only the form of
perception, consequently of objects as phenomena, that which in
objects corresponds to sensation is the transcendental matter of all
objects as things in themselves (thinghood, reality).[15] Now every
sensation has a