Much of the unsatisfactoriness of Kant’s argument is traceable to his
mode of conceiving the “construction”[525] of mathematical concepts. All
concepts, he seems to hold, even those of geometry and arithmetic, are
abstract class concepts--the concept of triangle representing the
properties common to all triangles, and the concept of seven the
properties common to all groups that are seven. Mathematical concepts
differ, however, from other concepts in that they are capable of _a
priori_ construction, that is, of having their objects represented in
pure intuition. Now this is an extremely unfortunate mode of statement.
It implies that mathematical concepts have a dual mode of existence,
first as abstracted, and secondly as constructed. Such a position is not
tenable. The concept of seven, in its primary form, is not abstracted
from a variety of particular groups of seven; it is already involved in
the apprehension of each of them as being seven. Nor is it a concept
that is itself constructed. It may perhaps be described as being the
representation of something constructed; but that something is not
itself. It represents the process or method generative of the complex
for which it stands. Thus Kant’s distinction between the intuitive
nature of mathematical knowledge and the merely discursive character of
conceptual knowledge is at once inspired by the very important
distinction between the product of construction and the product of
abstraction, and yet at the same time is also obscured by the quite
inadequate manner in which that latter distinction has been formulated.
Kant has again adhered to the older logic even in the very act of
revising its conclusions; and in so doing he has sacrificed the Critical
doctrines of the _Analytic_ to the pre-Critical teaching of the
_Dissertation_ and _Aesthetic_. _Mathematical concepts are of the same
general type as the categories; their primary function is not to clarify
intuitions, but to make them possible._ They are derivable from
intuition only in so far as they have contributed to its constitution.
If intuition contains factors additional to the concepts through which
it is interpreted, these factors must remain outside the realm of
mathematical science, until such time as conceptual analysis has proved
itself capable of further extension.