man; the corrupted philosopher is the worst; and the corrupted influences brought to bear are irresistible to all but the very strongest natures. The professional teachers of philosophy live not by leading popular opinion, but by pandering to it; a bastard brood trick themselves out as philosophers, while the true philosopher withdraws himself from so gross a world. Small wonder that philosophy gets discredited! Not in the soil of any existing state can philosophy grow naturally; planted in a suitable state, her divinity will be apparent. I need no longer hesitate to say that we must make our guardians philosophers. The necessary combination of qualities is extremely rare. Our test must be thorough, for the soul must be trained up by the pursuit of all kinds of knowledge to the capacity for the pursuit of the highest--higher than justice and wisdom--the idea of the good. "But what is the good--pleasure, knowledge?" No. To see and distinguish material things, the faculty of sight requires the medium of light, whose source is the sun. The good is to the intellectual faculty what the sun is to that of vision: it is the source and cause of truth, which is the light whereby we perceive ideas; it is not truth nor the ideas, but above them; their cause, as the sun is the source of light and the cause of growth. Again, as the material things with which the eye is concerned are in two categories--the copies, reflections or shadows of things, and actual things--correspondingly the things perceived by the intellect are in a secondary region--as the mathematical--where everything is derived from hypotheses which are assumed to be first principles; or in a supreme region, in which hypotheses are orly the steps by which we ascend to the real ultimate first principles themselves. And it will follow further that the mind has four faculties appropriate to these four divisions, which we call respectively pure reason (the highest), understanding, conviction, and perception of shadows; the first pair being concerned with being, the field of the intellect; the second pair with becoming, the field of opinion. _V.--Of Shadows and Realities_