Does not man lack the force at the very point where he needs it most? And when he soars upward in joy, or sinks down in suffering, is not checked in both, is he not returned again to the dull, cold sphere of awareness, just when he was longing to lose himself in the fullness of the infinite.

There are men who never err, because they never propose anything rational.

Reason can never be popular. Passions and feelings may become popular, but reason will always remain the sole property of a few eminent individuals.

Man knows himself only insofar as he knows the world, becoming aware of it if only within himself, and of himself self only within it. Each new subject, well observed, opens up within us a new organ of thought.

Love can do much, but duty more.

Animals, we have been told, are taught by their organs. Yes, I would add, and so are men, but men have this further advantage that they can also teach their organs in return.

Nature is, after all, the only book that offers important content on every page.