The Analytic/Synthetic Distinction
The analytic/synthetic distinction has been explicated in numerous ways and while some have deemed it fundamentally misguided (e.g., Quine 1961), it is still employed by a number of philosophers today.
One standard way of marking the distinction, which has its origin in Kant (1781), turns on the notion of conceptual containment.
By this account, a proposition is analytic if the predicate concept of the proposition is contained within the subject concept.
The claim that all bachelors are unmarried, for instance, is analytic because the concept of being unmarried is included within the concept of a bachelor. [ΑΝΑΛΥΣΗ ΣΥΝΘΕΤΗΣ ΕΝΝΟΙΑΣ]
By contrast, in synthetic propositions, the predicate concept “amplifies” or adds to the subject concept. [ΠΑΡΑΔΕΙΓΜΑΤΑ]
The claim, for example, that the sun is approximately 93 million miles from the earth is synthetic because the concept of being located a certain distance from the earth goes beyond or adds to the concept of the sun itself. [ΑΣΥΝΑΦΕΙΣ ΠΡΟΣΔΙΟΡΙΣΜΟΙ ΕΝΟΣ ΑΝΤΙΚΕΙΜΕΝΟΥ]
A related way of drawing the distinction is to say that a proposition is analytic if its truth depends entirely on the definition of its terms (that is, it is true by definition), while the truth of a synthetic proposition depends not on mere linguistic convention, but on how the world actually is in some respect.
The claim that all bachelors are unmarried is true simply by the definition of “bachelor,” while the truth of the claim about the distance between the earth and the sun depends, not merely on the meaning of the term “sun,” but on what this distance actually is.
Some philosophers have equated the analytic with the a priori and the synthetic with the a posteriori.
There is, to be sure, a close connection between the concepts.
For instance, if the truth of a certain proposition is, say, strictly a matter of the definition of its terms, knowledge of this proposition is unlikely to require experience (rational reflection alone will likely suffice).
On the other hand, if the truth of a proposition depends on how the world actually is in some respect, then knowledge of it would seem to require empirical investigation.
Despite this close connection, the two distinctions are not identical.
First, the a priori/a posteriori distinction is epistemological: it concerns how, or on what basis, a proposition might be known or justifiably believed.
The analytic/synthetic distinction, by contrast, is logical or semantical: it refers to what makes a given proposition true, or to certain intentional relations that obtain between concepts that constitute a proposition.
This raises the question of the sense in which a claim must be knowable if it is to qualify as either a priori or a posteriori. For whom must such a claim be knowable? Any rational being? Any or most rational human beings? God alone? There may be no entirely nonarbitrary way to provide a very precise answer to this question.