In philosophy, 'substance' is 'the bearer of attributes'. It is almost more like the word 'subject' as in, 'the subject X has the attribute Y'; it is not like 'substance' in the sense of some objective stuff; 'substance is that which is always subject, never predicate' (Kelly Ross).

'Subsists in' is sometimes used to indicate the manner of the existence of an attribute, as an attribute can't be said to exist separately from the substance/subject in which it inheres; can 'the blue of your eyes' be said to exist? Or does it depend on there being eyes, of which 'blue' is an attribute? That usage too is rather different from the usual meaning of 'subsistence'. In this context, 'subsists' and 'inheres in' are rather similar concepts.

(That's my understanding, picked up from various sources, someone else might know better.)

@Wayfarer Thanks a lot! I am just starting out with high school philosophy and have never come across any of the above-mentioned terms so the quick explanation was really helpful.

Just to clarify this in context of the argument, why would space and time, if considered properties of objects, not be able to inhere in substances? Would their existence as properties not be the very definition of them inhering in objects?

In his reductio ad absurdum, Kant goes on to state that this view must also suppose that space and time as properties would have to exist even if all existing things (those to which they apply) were removed. However, how can a property exist without the thing to which it applies?

As I said before, the English version I am reading is extremely concise to the point of summarizing some of Kant's statements but, for this particular argument, I can not make sense of the German original either.

This is the link in case I did not explain it accurately. The argument is on the right side of page 39.

http://www.earlymoderntexts.com/assets/pdfs/kant1781part1.pdf

Sorry if I am asking too much. I am just really confused about this section even though the conclusion of the argument makes sense.

Just to clarify this in context of the argument, why would space and time, if considered properties of objects, not be able to inhere in substances? Would their existence as properties not be the very definition of them inhering in objects? — Nino Millesi

The basic argument is that time and space are 'necessary intuitions' i.e. they are required in order for thinking and cognition to be possible at all. 'The idea of time itself cannot be gathered from experience because succession and simultaneity of objects, the phenomena that would indicate the passage of time, would be impossible to represent if we did not already possess the capacity to represent objects in time.' (from http://www.iep.utm.edu/kantmeta/)

Space can't be a property of objects, because objects exist in space; the reality of space and time are presupposed by the apprehension of any objects whatever (my paraphrase. But I don't get the 'reductio' argument you've summarised.)

I am just really confused about this section even though the conclusion of the argument makes sense. — Nino Millesi

No apologies are needed. Kant's Critique of Pure Reason is a very difficult work indeed, and anyone who tries to read it deserves credit in my view. But, it is often said to be the most important single work of modern philosophy, so definitely worth the effort of reading. I think the translations on Early Modern Texts are very helpful as the site owner is a good scholar and provides useful commentary. Stick with it, and anything that you find too difficult on first reading, put to one side for the time being and then keep going. The pieces might begin to drop into place later.

@Wayfarer

Space can't be a property of objects, because objects exist in space; the reality of space and time are presupposed by the apprehension of any objects whatever (my paraphrase. But I don't get the 'reductio' argument you've summarised.)

Sorry I just reread my original post and saw that I did not make clear which argument I am referring to. Kant was alluding to the absurd result of viewing space and time as properties that objects have in themselves.

Anyway, your explanation cleared everything up and both your posts were extremely helpful. Thank you!

I will definitely stick with it and read the Early Modern Text version more carefully.