A painter should begin every canvas with a wash of black, because all things in nature are dark except where exposed by the light.
Politics have no relation to morals
A life without love, is no life at all.
No counsel is more trustworthy than that which is given upon ships that are in peril.
To nature, since it is only by chance that they wear the human.
When you put your hand in a flowing stream, you touch the last that has gone before and the first of what is still to come.
Details make perfection, and perfection is not a detail.
The length of a man's outspread arms is equal to his height.
All knowledge which ends in words will die as quickly as it came to life, with the exception of the written word: which is its mechanical part.
Man and animals are in reality vehicles and conduits of food, tombs of animals, hostels of death, coverings that consume, deriving life by the .
The mind of the painter must resemble a mirror, which always takes the colour of the object it reflects and is completely occupied by the images of as many objects as are in front of it.
The smallest feline is a masterpiece.
Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.
The painter who draws merely by practice and by eye, without any reason, is like a mirror which copies every thing placed in front of it without being conscious of their existence.
I have always felt it is my destiny to build a machine that would allow man to fly.
Medicine is the restoration of discordant elements; sickness is the discord of the elements infused into the living body.
Our life is made by the death of others.
Each man is always in the middle of the surface of the earth and under the zenith of his own hemisphere, and over the centre of the earth.
As every divided kingdom falls, so every mind divided between many studies confounds and saps itself.
The function of muscle is to pull and not to push, except in the case of the genitals and the tongue.
Weight, force and casual impulse, together with resistance, are the four external powers in which all the visible actions of mortals have their being and their end.
Poor is the pupil who does not surpass his master.
Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.
Where there is shouting, there is no true knowledge.
Nature never breaks her own laws.
For, verily, great love springs from great knowledge of the beloved object, and if you little know it, you will be able to love it only little or not at all.
Men of lofty genius when they are doing the least work are most active.
Knowledge of the past and of the places of the earth is the ornament and food of the mind of man.
Beyond a doubt truth bears the same relation to falsehood as light to darkness.
Where the spirit does not work with the hand, there is no art.