Test knowledge through experience, be prepared to make mistakes, and be persistent about it.

I have from an early age abjured the use of meat, and the time will come when men such as I will look upon the murder of animals as they now look upon the murder of men.

O time, swift robber of all created things, how many kings, how many nations hast thou undone, and how many changes of states and of various events have happened since the wondrous forms of this fish perished here in this cavernous and winding recess. Now destroyed by time thou liest patiently in this confined space with bones stripped and bare; serving as a support and prop for the superimposed mountain.

Let the painter composing narrative pictures take pleasure in wealth and variety, and avoid repeating any part that occurs in it, so that the uniqueness and abundance attract people to it and delight the eye of the observer. I say that a narrative painting requires (depending on the scene), wherever the eye falls, a mixture of men of diverse appearances, of diverse ages and dress, combined together with women, children, dogs, horses, buildings, fields, and hills.

He who fears dangers will not perish by them.

O sleepers! what a thing is slumber! Sleep resembles death. Ah, why then dost thou not work in such wise as that after death thou mayst retain a resemblance to perfect life, when, during life, thou art in sleep so like to the hapless dead?

My body will not be a tomb for other creatures.