There is more evidence to prove that saltness [of the sea] is due to the admixture of some substance, besides that which we have adduced. Make a vessel of wax and put it in the sea, fastening its mouth in such a way as to prevent any water getting in. Then the water that percolates through the wax sides of the vessel is sweet, the earthy stuff, the admixture of which makes the water salt, being separated off as it were by a filter.

Through discipline comes freedom.

The soul is the form of the body

All men by nature desire to know. An indication of this is the delight we take in our senses; for even apart from their usefulness they are loved for themselves...

Bad people...are in conflict with themselves; they desire one thing and will another, like the incontinent who choose harmful pleasures instead of what they themselves believe to be good.

Wonder implies the desire to learn.

Everything necessarily is or is not, and will be or will not be; but one cannot divide and say that one or the other is necessary.I mean, for example: it is necessary for there to be or not to be a sea-battle tomorrow; but it is not necessary for a sea-battle to take place tomorrow, or for one not to take place--though it is necessary for one to take place or not to take place.