^A.C. Grayling, Philosophy 1: A Guide through the Subject (Oxford University Press, 1998), p. 1: "The aim of philosophical inquiry is to gain insight into questions about knowledge, truth, reason, reality, meaning, mind, and value."
^Sellars, Wilfrid (1963). Empiricism and the Philosophy of Mind (PDF). Routledge and Kegan Paul Ltd. pp. 1, 40.