Isocrates to Demonicus – Noble Maxims

No adornment so becomes you as modesty, justice, and self-control; for these are the virtues by which, as all men are agreed, the character of the young is held in restraint.

Practice self-control and do not fall under the sway of temper, pleasure, and pain.

Abhor flatterers as you would deceivers; for both, if trusted, injure those who trust them. 

Be affable in your relations with those who approach you, and never haughty; for the pride of the arrogant even slaves can hardly endure.

Be slow in deliberation, but be prompt to carry out your resolves.

The best thing which we have in ourselves is good judgment.

Constantly train your intellect for the greatest thing in the smallest compass is a sound mind in a human body.