This section concerns Frege's desire to show arithmetic independent of Kantian intuitions.
It begine with some discussion of schematization, about which I am unable to comment.

From that discussion the authors then extract some desiderata for an account of number independent of Kantian Intuition, viz:

- must explain applicability of numerical concepts
- must explain the
*reference* of arithmetical equations and inequations
- must recover any piece of arithmetical reasoning (of certain kinds)

all without dependence on intuitions.

I am inclined to reject all of this.
The applicability of arithmetic does not depend upon how the number system is established.
A wholly satisfactory account of arithmetic need not identify even what the numbers are, let alone what equations and inequations
refer to, I have no inkling of why these referents should be thought important.
Of course, a definition of the natural numbers will be useful mathematically only if it is done in a context which permits
one to do number theory, but this provides no basis for discriminating between alternative definitions, which need only to
say enough to yield the right kind of structure.

My reaction is of course based on a twentieth century understanding of how the natural numbers can be defined, and are therefore
naturally more in line with Frege's than Kant's perspective, though I would not myself object to the idea that intuition has
a role to play, both in coming up with a definition of number and in applying it.