In his presidential address to the American Philosophical Association in 1955 Ernest Nagel expounded and defended a philosophy he called naturalism, despite the fact that “the number of distinguishable doctrines for which the word ‘naturalism’ has been a counter in the history of thought is notorious … ” [Nagel, 1956, p. 3]. In retrospect what was distinctive about Nagel's naturalism was its radical departure from the modern western tradition in epistemology. Nagel rejected as an objection to naturalism the charge that it does not secure independently any warrant for the epistemic role it accords the methods of science. According to this objection, in committing itself to the logic of scientific proof without further foundations, naturalism is quite analogous to religious belief in resting on unsupported and indemonstrable faith. Such an argument, Nagel wrote,