Wednesday, March 08, 2006
A Student Question about Kant (by W. Kilgore)
According to Kant, there are some synthetic propositions that are a priori. These include time and space. Why did Kant consider these propositions to be synthetic? Kant says that these propositions are a priori becuase they are an innate feature of our mind. Their function is to organize the information we percieve from the world. I understand why he considers them a priori, but I am confused about why he considers them synthetic propositions. By definition, a synthetic proposition is a posteriori and known by experience, while an analytic proposition is a priori and known before experience. Why aren't the a priori synthetic statements just considered analytic statements? They are innately known and do not require experience, so they should be, by definition, analytic.
Answer:
Kant said one of the difficutlies with human reason is that it leads us to ask questions that it cannot answer. The same may be said, mutatis mutandis, of our textbook. Your question is an important one. Space and time, in themselves, of course, are not propositons at all, since they are not assertions. They are what Kant called the a priori forms under which objects of the senses can be intuited. All our external intuitions ( = perceptions, more or less) require the form of space, and our internal intuitions (memory, thought) require the form of time.
Analytic propositions do not require the perception of external objects, and therefore they do not require the a priori form (or format, of you like) of spatiality. Neither do the supply us with any new information about the world, as synthetic propositions do. Analytic propositions are so called because they ana-lyse (separate or break down) the information already contained in the subject, but expressing an aspect of it as a predicate (Bachelors are men). Synthetic propositions (syn = together) bring together a subject with a predicate that contains new information not implicit in the subject (The table is green). Now since we must perceive an object in order to predicate anything about it, such synthetic propositions are a posteriori. One the other hand, since the perception of external objects is only possible in the form of spatiality, and that form of spatiality is a priori, i.e. brought to the world by the mind of the perceiver, it may also be said that such propositions have an a priori basis or prior condition. As Kant says: "What we can know a priori--before all real intuition, are the forms of space and time, which are therefore called pure intuition, while sensation is that which causes our knowledge to be called a posteriori knowledge, i.e. empirical intuition." (Critique of Pure Reason, Müller translation, p. 36) Now this obviously does not solve all our problems, because it would seem that we are left with propositions that would have to be classified as both a priori and a posteriori, which would leave us with a glaring contradiction (A and not-A). I am not enough of a Kantian to lead you any further with the requisite degree of certainty on this question, Whitney, but I have a feeling that Kant's solution would be to introduce two layers here, the pure intuition (which does not have real objects as its focus) and the empirical intuition, that does have real objects (and hence sensations as well). The former sort of proposition would constitute a precondition of the latter, and be implied in the latter. But do not take my hypothesis for more than what it is. To make matters more complex, Kant wrote a second version of his Critique of Pure Reason, so that both would have to be considered carefully before a definitive answer to your question could be given.
Dr. Michael Papazian said...
This is an interesting and important question. If I understand the question correctly, you are asking why Kant considers propositions about space and time to be synthetic, since synthetic propositions are a posteriori and known by experience. But Kant doesn't think that synthetic propositions are a posteriori by definition (Hume did, but that's a point on which the two disagreed). As Dr. Smith pointed out, synthetic propositions are simply those whose predicate terms add information not contained in the meaning of the subject ("Bachelors are unhappy" vs. "Bachelors are men.")
Now when Kant says that propositions about space and time are synthetic a priori, he is talking about specific kinds of such propositions, especially those that are used in arithmetic and geometry, such as 7+5=12. One way of thinking about this is that you can have the concept of 7 and 5 but not 12 (supposedly some primitive socieites only count up to a certain number; everything after 10, let's say, is called "many"). So 12 is adding something to the concept of 7+5 that presupposes we're counting on a linear open-ended number line (as opposed to, say, a clock, where 7+6 =1, not 13, since there is no 13 o'clock). So we need to have an idea of an infinite number line to be able to add as we do. Where does that come from? From our a priori conception of time as linear. Hence, 7+5=12 is a priori--we don't need any particular experience of the world to know it is true. But it is also synthetic because it depends on the way in which we conceptualize and understand time in order to be known. By contrast, 7+5=7+5 is analytic, because that is true whether we're using "line" arithmetic or "clock" arithmetic or whatever arithmetic there may exist.
I hope that this helps out in understanding an extremely complex but fascinating aspect of Kant's philosophy.