Quine, Willard Van Orman

"The question 'What is there?' has no answer independent of a framework."

"Logical truth is true in all possible worlds we care to imagine."

"Classical logic may not be the best system for all domains."

"Mental entities are theoretical posits like any others."

"We should preserve our most useful theories at the cost of revising others."

"Platonism about mathematics requires no more than pragmatic acceptance."

"The mind is not a mirror of nature but an active interpreter."

"Quantification is the key to ontological commitment."

"We bind ourselves to theories by using quantified variables."

"Essence is a matter of convention, not discovery."

"Every statement has some degree of empirical content."

"Reductionism fails because the whole is not merely the sum of its parts."

"Meaning is constituted by relations, not by intrinsic properties."

"We should be suspicious of distinctions that cannot be operationally defined."

"Extensionality has limits—intensional contexts resist it."

"The scope of a quantifier matters more than we initially thought."

"Nominalism and realism represent different choices, not different truths."

"Stimulus equivalence is the most objective standard of meaning."

"We know the world as it appears to us through our theories."

"The analytic-synthetic distinction blurs upon close examination."

"Necessity derives from language, not from the world."

"Our best theory of the world determines what we should believe exists."

"Identity statements involving proper names are conventional."

"The unity of science is an ideal, not a doctrine."

"Observation sentences are the touchstone of empirical meaning."

"We adopt the simplest theory consistent with our observations."

"Abstract objects have no causal powers, yet we cannot do without them."

"The set-theoretic hierarchy is a useful fiction for organization."

"Ontological reduction is often more trouble than it is worth."

"We should quantify over whatever we need to make our best theories true."