One of the oldest and most problematic philosophical questions is the comparison of the a priori–a posteriori distinction with that of the analytic–synthetic distinction. Both are used in epistemology to divide knowledge, or true statements, between the innate and the learned, or the immediate and the earned, so they might even be considered the same. A priori and a posteriori statements are before “experience” and after it, respectively. Analytic statements are true only by their “meaning”, whereas synthetic statements are true only when facts about the world are combined consistently with that meaning.
It seems we have complicated the issue because now we must define and understand “experience” and “meaning”. However, these concepts are not independent because we must experience meaning, and meaning in turn conditions experience. In addition, even the a priori or the analytic are not innate or immediately obvious because deductions and the rules of logic require effort just like inductions do. Otherwise we would have Fitch’s Paradox: all truths are in fact known. What a muddle! So both experience and meaning are necessarily locked into a cooperative spiral dance to improve each other.
In addition, if you search for the two pairs a priori-a posterior and analytic-synthetic, you also find that the pair necessary-contingent is associated with them. Are these three pairs independent of one another and so give rise to eight triplets, or are they dependent in some way and reduce into fewer combinations? In addition, from Wikipedia:
Thus, the relationship between aprioricity, necessity, and analyticity is not easy to discern. However, most philosophers at least seem to agree that while the various distinctions may overlap, the notions are clearly not identical: the a priori/a posteriori distinction is epistemological, the analytic/synthetic distinction is linguistic, and the necessary/contingent distinction is metaphysical.
The web site of Stephen R. Palmquist has a great wealth of material on fourfolds in relation to Kant’s as well as his own philosophy. From my own initial reading of his extensive material I have tried to choose a canonical Kantian fourfold which has the most relevance to my project.
The fourfold shown to the right Dr. Palmquist calls Kant’s “reflective perspectives on experience”. Consisting of the logical, the empirical, the transcendental, and the hypothetical, these facets bear a close analogical likeness to many of the fourfolds presented here.
Logical: Analytic a priori
Transcendental: Synthetic a priori
Hypothetical: Analytic a posteriori
Empirical: Synthetic a posteriori
Dr. Palmquist also has many of his own books available on his web site for the interested reader. I will certainly be returning to his web site in the future for much enjoyable study.
A Priori-A Posteriori, Analytic-Synthetic, and Necessary-Contingent Distinctions
[*7.68, *7.84, *8.126, *10.54]