All soul is immortal. For that which is always in movement is immortal; that which moves something else, and is moved by something else, in ceasing from movement ceases from living. So only that which moves itself, because it does not abandon itself, never stops moving. But it is also source and first principle of movement for the other things which move.

If one has made a mistake, and fails to correct it, one has made a greater mistake.

How can you prove whether at this moment we are sleeping, and all our thoughts are a dream; or whether we are awake, and talking to one another in the waking state?

One trait in the philosopher's character we can assume is his love of the knowledge that reveals eternal reality, the realm unaffected by change and decay. He is in love with the whole of that reality, and will not willingly be deprived even of the most insignificant fragment of it - just like the lovers and men of ambition we described earlier on.

As it is, lovers of inquiry must follow their beloved wherever it may lead.

The real tragedy of life is when men are afraid of the light.

The greatest wealth is to live content with little.