This paper deals with two opposite metaphilosophical doctrines concerning the nature of philosophy. More specifically, it is a study of the naturalistic view that philosophical, hence also epistemological, knowledge cannot be distinguished from empirical knowledge, and of the antinaturalistic view that philosophical, hence also epistemological, knowledge, is pure, that is, independent of empirical knowledge and particularly of the special sciences. The conditions of the possibility of naturalistic and of pure epistemology are studied in terms of phenomenological philosophy. It is concluded (...) that pure epistemology is possible under relatively strong conditions but that the version of naturalistic epistemology which denies the pure basis leads to contradiction. That, however, does not shake the possibility of cognitive science. Following Husserl, we may argue that studies of human cognition are possible on the condition that a first basis is assumed which is not naturalized. (shrink)