Let no man who is not a Mathematician read the elements of my work.

Although human ingenuity may devise various inventions which, by the help of various instruments, answer to one and the same purpose, yet will it never discover any inventions more beautiful, more simple or more practical than those of nature.

As a well-spent day brings happy sleep, so a life well spent brings happy death.

We see the most striking example of humility in the lamb which will submit to any animal; and when they are given for food to imprisoned lions they are as gentle to them as to their own mother, so that very often it has been seen that the lions forbear to kill them.

He who sows virtue reaps glory.

Patience serves as a protection against wrongs as clothes do against cold. For if you put on more clothes as the cold increases, it will have no power to hurt you. So in like manner you must grow in patience when you meet with great wrongs, and they will be powerless to vex your mind.

He who wishes to be rich in a day will be hanged in a year.

Man and animals are in reality vehicles and conduits of food, tombs of animals, hostels of Death, coverings that consume, deriving life by the death of others.

It is ordained that to the ambitious, who derive no satisfaction from the gifts of life and the beauty of the world, life shall be a cause of suffering, and they shall possess neither the profit nor the beauty of the world.

We are deceived by promises and time disappoints us...

He who in reasoning cites authority is making use of his memory rather than of his intellect.

Reserve the great matters till the end, and the small matters give at the beginning.

Why are the bones of great fishes, and oysters and corals and various other shells and sea-snails, found on the high tops of mountains that border the sea, in the same way in which they are found in the depths of the sea?

Avoid the precepts of those thinkers whose reasoning is not confirmed by experience.

Shadow is not the absence of light, merely the obstruction of the luminous rays by an opaque body.

In the first place, sculpture is dependent on certain lights, namely those from above, while a picture carries everywhere with it its own light and shade; light and shade therefore are essential to sculpture. In this respect, the sculptor is aided by the nature of the relief, which produces these of its own accord, but the painter artificially creates them by art in places where nature would normally do the like. The sculptor cannot render the difference in the varying natures of the colors of objects; painting does not fail to do so in any particular. The lines of perspective of sculptors do not seem in any way true; those of painters may appear to extend a hundred miles beyond the work itself. The effects of aerial perspective are outside the scope of sculptors' work; they can neither represent transparent bodies nor luminous bodies nor angles of reflection nor shining bodies such as mirrors and like things of glittering surface, nor mists, nor dull weather, nor an infinite number of things which I forbear to mention lest they should prove wearisome.

Experience is a truer guide than the words of others.

One can have no smaller or greater mastery than mastery of oneself.

All our knowledge is the offspring of our perceptions.

We should not desire the impossible.

That which has no limitations, has no form.

Just as courage is the danger of life, so is fear its safeguard.

Blinding ignorance does mislead us. O! Wretched mortals, open your eyes!

That which can be lost cannot be deemed riches.

Darkness is absence of light.
Shadow is diminution of light.

The part always has a tendency to reunite with its whole in order to escape from its imperfection.

Where there is most feeling, there is the greatest martyrdom.

All bodies together, and each by itself, give off to the surrounding air an infinite number of images which are all-pervading and each complete, each conveying the nature, colour and form of the body which produces it.

As every divided kingdom falls, so every mind divided between many studies confounds and saps itself.

He who possesses most must be most afraid of loss.