O painter skilled in anatomy, beware lest the undue prominence of the bones, sinews and muscles cause you to become a wooden painter from the desire to make your nude figures reveal all.

Nothing strengthens authority so much as silence.

Those who, in debate, appeal to their qualifications, argue from memory, not from understanding.

Reprove your friend in secret and praise him openly.

Vitality and beauty are gifts of Nature for those who live according to its laws.

Inaction saps the vigor of the mind.

Obstacles cannot bend me. Every obstacle yields to effort.