Explanation Of Kant's Transcendental Idealism

Transcendental idealism – In our talk about transcendental idealism we looked towards page 32 in Dicker, where we found the quotes of Kant saying that, "the conditions of space and time [are] conditions which are originally inherent in the subject." (A43/B60) Combined with Kant's idea that "space and time are the necessary conditions of all outer and inner experience" (A48-49/B 66), we found that we could understand what exactly Kant meant by his transcendental idealism. Essentially, space and time are constructs of a subject used to organize the intuitions received. Space and time are the medium through which we understand and experience things. One question that arises frequently when talking about transcendental idealism is the problem of not being able to actually experience something in itself, but rather only through space and time. A good way to explain this is the example of the man who is 10,000 light years tall. Observer A is on a planet next to the man's feet, while Observer B is on a planet next to the man's arm. The man then raises his arms and his legs at the same time. Observer A would see the man's legs move first before his arms, while Observer B would see the man's arms move before his legs. This shows how what we
intuit and perceive is affected by space and time.

Why space must be synthetic a priori
Another topic we discussed was the argument behind Kant's claim that space must be considered a synthetic a prior concept.
The only other possible claim would be that space is synthetic a posteriori – that our intuitions of space are based upon experience. It does not seem to follow that one could experience space and then have intuitions of it sufficient enough to create the concept of space – for if one did not originally have the idea of space, how would one be able to take independent objects and be able to differentiate them at all? It seems that in order to perceive anything as distinct from anything else, it is necessary to already have the concept of space and the idea that different things occupy different
spaces.
After proving that space must be a synthetic a priori concept, we moved onto the question of how Kant can prove that geometrical propositions are synthetic a priori. We came to the conclusion that the because space is a synthetic a priori concept, it follows that geometry, which is essentially the relations of points in space must also be. In this regard, a triangle is always going to exist as a triangle, whether or not we have experienced it, as the laws of space dictate it as such.