Source: p 137, Philosophy: A Complete Introduction (2012) by Prof. Sharon Kaye MA PhD (in Philosophy, U. Toronto)

10 Which of the following are things-in-themselves, in Kant's view?
a) Actions that conform to the moral law   b) Physical objects   c) Time and space
d) Perfectly rational minds

  1. The answer key (on p 220) states (b) as the only answer. But is this correct?

  2. I am conjecturing that a) is incorrect because they can be performed by humans and so are Phenomenal.

  3. Why is c) not also an answer? The following quote appears to justify c):

[p 128:] What would the world be like without time or space?

No one knows. No one can know. It's impossible for us to conceive of the world except through these concepts. Kant calls the physical world as it would be without the human concepts of time and space the noumenal realm, from the Greek word for 'thought'. The noumenal realm consists of things-in- themselves and transcends human experience.

  1. Why is d) not also an answer? Anything perfect does not exist for humans, and so must be Noumena?

1 Answer 1


With regards to "space and time", there's several problematic things happening at once which make them ineligible for being "things in themselves." For Kant, what is clear is that time and space are the conditions of sensibility, i.e. they are (at a minimum) a framework our mind applies to things in order to convert them into representations. These representations are then taken under the categories (a similar sort of application of our minds) to render things objects.

Whatever else they are, they are not themselves things -- and this is where there's great debate among contemporary Kant scholars centering around whether Kant is suggesting that space and time are merely conditions we apply to sensible things to make them representations (Vorstellung) or whether space and time have a separate metaphysical existence that relates in some other way to our mind's need to apply categories. For way too much reading on this, you can look at Kant's view on space and time at the SEP.

With respect to "perfectly rational minds" (d), the waters here are going to pretty murky. And this is an area where I think I disagree with at least two common posters. First and foremost, a perfectly rational mind is going to be noumenal since it is going to be able to act as a law for itself and undertake actions without being subject to laws of nature (i.e. determination).

The question, however, is whether something being noumenal makes it identical with a thing-in-itself. Both are inaccessible to the forms of representation (time and space) and the twelve categories of the understanding. Things-in-themselves are inaccessible since as they pass through the "meat-grinder", they become representations which are somewhat accessible and objects which are things we can know.

Wikipedia and several articles capture the debate. I think the strongest evidence in favor is that Kant does at one point identify the two. Guyer and Wood (quoted at wikipedia) note:

The concept of a noumenon, i.e., of a thing that is not to be thought of as an object of the senses but rather as a thing-in-itself [...]"; But note that the terms are not used interchangeably throughout. The first reference to thing-in-itself comes many pages (A30) before the first reference to noumenon (A250).

For some this is enough to identify thing-in-itself with noumenon. But that doesn't fully resolve things. A further question is whether there is something it is like to be a thing-in-itself. And then whether on Kant's view there's anything we can know about noumenals.

Judging by the author's choice, I would say the author does not think the two are identical. Instead, she sees the rational mind as a type of active will with powers.

For "Actions that conform to the moral law", it's not clear these are things that have their own separate existence at all. And if they don't they cannot be things-in-themselves. But I would say you're getting it wrong when you suggest "they can be performed by humans and so are Phenomenal."

Instead, I would suggest that these actions qua actions in conformity with the moral law cannot be seen as such in the phenomenal world since the conformity does not happen there. (This account is repeated across Groundwork, Critique of Practical Reason, Metaphysics of Morals, and Religion)

  • +1. Thanks. About A further question is whether there is something it is like to be a thing-in-itself., is this written exactly as intended? I interpret it as A further question is whether there is something [...] like to be a thing-in-itself..
    – user8572
    Mar 17, 2016 at 16:59
  • 1
    The wording is as I intended (whether that means its the best possible wording or not I don't know), but the idea it expresses is that there's an open question of whether there is anything qualitative at all about things-in-themselves or whether they are completely amorphous in-and-of-themselves like Aristotle's pure matter.
    – virmaior
    Mar 17, 2016 at 23:21

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