[12] The drift of the passage would seem to be this: 'If we
are to present to ourselves an instance of a quantity, we
must successively combine similar units until they form a
quantity. This process involves the thought of a successive
process by which we add units according to the conception 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.