Oh! Speculators on things, boast not of knowing the things that nature ordinarily brings about; but rejoice if you know the end of those things which you yourself device.

Those who condemn the supreme certainty of mathematics feed on confusion, and can never silence the contradictions of the sophistical sciences which lead to eternal quackery.

The moment is timeless.

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.

The first object of the painter is to make a flat plane appear as a body in relief and projecting from that plane

Iron rusts from disuse; water loses its purity from stagnation... even so does inaction sap the vigor of the mind.

Old age takes in part savoury wisdom for its food - see to that your old age will not lack in nourishment.