Nominalism, Berkeley and Kant -- (transcendental) ideality of space

In his Three Dialogues Between Hylas and Philonous, Berkeley argued for the ideality of "extension in general" from a nominalist position.

it is a universally received maxim that EVERYTHING WHICH EXISTS IS PARTICULAR. How then can motion in general, or extension in general, exist in any corporeal substance?

One might equally argue from the nominalist premise that

P1) everything that exists is particular -- universals do not exist

P2) space in general is not a particular, but a universal

therefore

C1) space in general does not exist.

(For the record, I am not a nominalist)

Kant held that space was empirically real, but transcendentally ideal. As far as I understand him on this point, he claims that 1) space is given to us through experience, so it is empirically real, but 2) space does not exist "in-itself", and so it is transcendentally ideal.

Kant could have used a modified version of the nominalist claim that

P1A) everything that is transcendentally real is particular -- universals are transcendentally ideal

P2) space per se is not a particular, but a universal

therefore

C1A) space per se is transcendentally ideal

Kant could have raised this argument, similar to Berkeley's argument. However, I don't know whether he actually did. (I once attempted to read Critique of Pure Reason on my own, but became quite baffled.) So my question is:

Did Kant raise a nominalist argument (something similar to the argument described above) in favor of his conclusion that space is empirically real but transcendentally ideal? If so, a quote would be appreciated.

The key point is: particular vs general.

For Kant, Space and Time are neither individuals nor general concepts.

For Kant there is a fundamental epistemological distinction:

The intuition/concept distinction,

grounded in the distinction between two different cognitive faculties: understanding and sensibility.

Kant says that:

"An objective perception is cognition (cognitio). This is either intuition or concept (intuitus vel conceptus). The first relates immediately to the object and is singular; the second is mediate, conveyed by a mark, which can be common to many things. A concept is either an empirical or a pure concept, and the pure concept, insofar as it has its origin solely in the understanding (not in a pure image of sensibility), is called notio. A concept made up of notions, which goes beyond the possibility of experience, is an idea or a concept of reason. (A320/B376–7)."

Representation contains sensations [Empfindungen], intuitions [Anschauungen], and concepts [Begriffe]. Sensibility generates representations based on being affected either by entities distinct from the subject or by the subject herself. This is in contrast to the faculty of understanding, which generates conceptual representations spontaneously – i.e. without advertence to affection. Reason is that spontaneous faculty by which special sorts of concepts, which Kant calls ‘ideas’ or ‘notions’, may be generated, and whose objects could never be met with in “experience,” which Kant defines as perceptions connected by fundamental concepts.

We have to stress the fact that intuition, for Kant, is of the individual: it needs experience.

Concept instead is general: there are no individuals in the realm of concepts.

Knowledge requires the relation of concepts to sensible intuitions.

Finally:

Kant claims that all the representations generated via sensibility are structured by two “forms” of intuition—space and time—and that all sensory aspects of our experience are their “matter” (A20/B34).

In conclusion, Kant is not a nominalist: there are general concepts.

Kant is an idealist, in a peculiar way: a transcendental idealist.