The mystically inclined who glory in their anti-rationality and impracticality may play the part of intellectual babes and worldly boobs if they wish to do so. But the philosophically inclined, realizing that they live in an era where the evil forces against which they must struggle have reached unparalleled intensity and revealed the most diabolic cunning, realize that they cannot afford such a luxury. They will consequently foster all the practical shrewdness, the critical intelligence, observance, and alertness they can summon up.
-- Notebooks Category 20: What Is Philosophy? > Chapter 4: Its Realization Beyond Ecstasy > # 28