In Paul Guyer's Kant, section "Space and Time: the pure forms of sensible intuition", Guyer argues that "Kant’s argument for transcendental idealism is incomplete."
For that, he gives two arguments. The first is basically that Kant merely asserts that space is a priori, dismissing some possible alternatives, which I can follow. The second one is a bit more tricky for me - I can see it in a certain logical way, but I can't imagine how things would be if we did not make this assumption. These are Guyer's words:
Second, he is assuming that we can say of any particular object that we perceive in space and time that it necessarily has the spatial and/or temporal properties that we perceive it to have.
I thought that space and time, as a priori intuitions are precisely the "rules" with which we perceive objects. So the alternative path for this assumption would be something like "our perception has rules but its objects don't really conform to them". Could someone clarify this?
In more Kantian terms, I'm guessing that for this to be true we would need to separate
- the "form of sensibility" that holds the rules which sensations would really conform to, and
- the "singular intuitions of space and time", a simplification of the form of sensibility.
Would that be correct? What would be the implications of this scenario? Couldn't Kant raise a contention here that in this case the second is not anymore the "singular intuitions of space and time", but "singular intuitions of simplifications of space and time", and that we would necessarily have another "singular intuitions of space and time"?
To be clear, I'm not (only) asking why Kant holds the views he does, but how it could be possible for Guyer to consider the second assumption to be false, and if it were false, what that would imply.