system
Given the following post, respond as if you're commenting on Reddit:
human
Why does Kant believe that space and time are 'intuitions' and not 'concepts'?

I'm currently making my way through the Transcendental Aesthetic in the first critique, and while I understand Kant's claims that space and time are a priori forms of intuition, I don't understand his arguments that claim that they are intuitions and not concepts.

I'm thinking perhaps the misunderstanding is arising from not fully understanding what Kant means by a concept. If anyone can shed some light on this that'd be appreciated.
gpt
Kant argues for why he thinks space and time are a priori and are originally intuitions rather than concepts in the aesthetics. See around B38 where argument for space being an a priori intuition starts. 

For Kant, you can have concepts of space and time, but their "original representations" are intuitions. 

For Kant, intuitions (not to be confused with colloquial use of the term; Kant's intuition has almost no relation to the ordinary sense of the word today) are representations that directly (immediately) relate to its objects. For humans, intuitions are associated with sensibility that is the ability to recieve sense matter. "Roughly" speaking, intuitions are more "raw" ("unconceptualized") representations. Concepts, on the other hand, operates from the faculty of understanding at a discursive level through our intuition i.e it doesn't directly related to its objects but relate to them through our sensible intuitions. 


For Kant intuition are of particular/singular objects whereas a concept can be somewhat like a universal - it can denote some element which is possessed by multiple representations (for example, the concept "red" can be possessed by multiple colored objects). However, Kant believes concepts themselves cannot contain within itself an infinite representations; whereas intuitions can have a sort of infinity (or unboundness) in it. Kant believes space and time has this sort of infinity. As Kant argues space is singular (there is purpotedly only one space), and it can present an inifnity of spatial objects in it. Kant believes all these fit space being an intuition rather than a concept. There are similar arguments for time.