ウィラード・ヴァン・オーマン・クワイン
"No entity without identity".
Ontology recapitulates philology". (Attributed to James Grier Miller in the epigraph of Word and Object)
"Philosophy of science is philosophy enough".
"To be is to be the value of a bound variable". (From "On What There Is")
"The Humean predicament is the human predicament".
"Quantification is the ontic idiom par excellence".
"We cannot stem linguistic change, but we can drag our feet. If each of us were to defy Alexander Pope and be the last to lay the old aside, it might not be a better world, but it would be a lovelier language" (Quiddities is chock-full of similar sentiments).
Set Theory and Its Logic. Quine proposes yet another flavor of axiomatic set theory, then derives the foundations of mathematics therefrom; includes the definitive treatment of Quine's theory of virtual sets and relations. Fraenkel, Bar-Hillel and Levy (1973) do a better job of surveying set theory as it stood in the 1950s.
All five texts remain in print. Curiously, advocates of Quinian set theory are not warm to the axiomatic set theory Quine advocated in his two advanced texts, and invariably confine their enthusiasm to NF and offshoots thereof proposed by others.