Another difference between a Philosopher and a Mystic is the following: the Mystic may be illiterate, uneducated, simple-minded, but yet may attain the Overself. Thus he finds his Inner Peace. It is easier for him because he is less intellectual, hence has fewer thoughts to give up and to still. But Nature does not absolve him from finishing his further development. He has still to complete his horizontal growth as well as balance it. He has obtained depth of illumination but not breadth of experience where the undeveloped state of faculties which prevents his light from being perfect may be fully developed. This can happen either by returning to earth again or continuing in other spheres of existence; he does all this inside his peace instead of, as with ordinary man, outside it. When his growth is complete, he becomes a philosopher.
-- Notebooks Category 20: What Is Philosophy? > Chapter 4: Its Realization Beyond Ecstasy > # 11