Q&A: Synthetic A Priori
Synthetic A Priori
Question
In chapter 6 of Gate 12 in his book Two Carts and a Hot-Air Balloon, the Rabbi presents the contradiction between foreknowledge and free choice (or between any pair of independent concepts) as an example of synthetic a priori propositions—and emphasizes the fact that the relation is the synthetic a priori part.
I didn’t understand this part. Seemingly, the synthetic a priori part is not the relation between the concepts but their definitions. Once there are definitions, one can seemingly point to the contradiction between them analytically. For example:
A) At every junction I can choose any option I want.
B) God knows what is going to happen and therefore also what I will choose.
C) If I can choose anything, then I can also choose the option that God “knows” I will not choose. Consequently, either He is mistaken or I cannot choose it. In any case, we have arrived at a contradiction.
And therefore it seems that דווקא the definition of the concept is the synthetic a priori proposition—because it arises from observation through the “eyes of the intellect,” (and not the presentation of the contradiction, which actually seems more like the stage in the argument that we carry out by means of our analytic part). So I did not understand why the Rabbi emphasizes דווקא the contradiction..?
Answer
First, it is not “a contradiction between any pair of independent concepts” but “any contradiction between a pair of independent concepts” (not every pair of independent concepts is contradictory). My claim is that if there is a contradiction between two independent concepts, it is never analytic, but rather either synthetic a priori (it contradicts our basic intuitions—not logic and not the facts) or fully a posteriori (factual).
The example you gave is incorrect. Clause C does not exist (it is impossible to choose the option that God does not know, because there is no such option. You cannot choose a non-existent option, like a square circle). And that is exactly what proves that you will not succeed in reaching an analytic contradiction unless you force it by hand into your definitions of the concepts. But that is not interesting. The interesting contradictions are those that arise between pairs of concepts whose definitions are known and familiar independently (not ones that I define now in order to show that there is a contradiction between them).
And as for your question, that is exactly the answer. The definitions of knowledge and choice are known to me from the general use of these concepts. The contradiction arises from my analysis. Therefore the contradiction is the interesting part that is worth discussing, and it is synthetic a priori.