Quintilian

When defeat is inevitable, it is wisest to yield.

It is worth while too to warn the teacher that undue severity in correcting faults is liable at times to discourage a boy's mind from effort.

Nothing is more dangerous to men than a sudden change of fortune.

To my mind the boy who gives least promise is one in whom the critical faculty develops in advance of the imagination.

A liar should have a good memory.

Our minds are like our stomaches; they are whetted by the change of their food, and variety supplies both with fresh appetite.

The perfection of art is to conceal art.

Men, even when alone, lighten their labors by song, however rude it may be.