"Two Dogmas of Empiricism" is a paper by analytic philosopher Willard Van Orman Quine published in 1951.
Quine begins by making a distinction between two different classes of analytic statements.
To exclude that example and some other obvious counterexamples, such as poetic quality, Quine introduces the notion of cognitive synonymy.
It seems that the only way to assert the synonymy is by supposing that the terms 'bachelor' and 'unmarried man' are synonymous and that the sentence "All and only all bachelors are unmarried men" is analytic.
But for salva veritate to hold as a definition of something more than extensional agreement, i.e., cognitive synonymy, we need a notion of necessity and thus of analyticity.
"So, if the verification theory can be accepted as an adequate account of statement synonymy, the notion of analyticity is saved after all."
So some form of reductionism - "the belief that each meaningful statement is equivalent to some logical construct upon terms which refer to immediate experience" - must be assumed in order for an empiricist to 'save' the notion of analyticity.
Quine first observes that Carnap's starting point was not the strictest possible, as his "sense-datum language" included not only sense-events but also "the notations of logic, up through higher set theory... Empiricists there are who would boggle at such prodigality."
Finally, Quine objects in principle to Carnap's proposed translation of statements like "quality q is at point-instant x;y;z;t" into his sense-datum language, because he does not define the connective "is at".
Until a reductionist can produce an acceptable proof, Quine maintains that reductionism is another "metaphysical article of faith".
He states also that a revision of the law of excluded middle has been proposed as a means of simplifying quantum mechanics.
Quine is a physicalist, in the sense that he considers it a scientific error not to adopt a theory which makes reference to physical objects.
Rudolf Carnap prepared a reply entitled "Quine on Analyticity", but this was not published until 1990.
Carnap then puts forward that an exact artificial language ought to clarify the problem by defining 'green' (or its synonym) as something that is either necessarily or contingently not applied to space-time points.
Carnap also answers Quine's argument on the use of sets of formal sentences to explain analyticity by arguing that this method is an explication of a poorly understood notion.
They also draw the conclusion that discussion about correct or incorrect translations would be impossible given Quine's argument.
Four years after Grice and Strawson published their paper, Quine's book Word and Object was released.
In Two Dogmas' revisited, Hilary Putnam argues that Quine is attacking two different notions.
Putnam considers the argument in the two last sections as independent of the first four, and at the same time as Putnam criticizes Quine, he also emphasizes his historical importance as the first top rank philosopher to both reject the notion of apriority and sketch a methodology without it.
[3] Jerrold Katz countered the arguments of Two Dogmas directly by trying to define analyticity non-circularly on the syntactical features of sentences.