I love those who can smile in trouble, who can gather strength from distress, and grow brave by reflection. 'Tis the business of little minds to shrink, but they whose heart is firm, and whose conscience approves their conduct, will pursue their principles unto death.

Art is never finished, only abandoned.

The human foot is a masterpiece of engineering and a work of art.

Where the spirit does not work with the hand, there is no art.

A beautiful body perishes, but a work of art dies not.

There are three classes of people: those who see, those who see when they are shown, those who do not see.

Just as courage imperils life, fear protects it.

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

Experience never errs; it is only your judgments that err by promising themselves effects such as are not caused by your experiments.

Although nature commences with reason and ends in experience it is necessary for us to do the opposite, that is to commence with experience and from this to proceed to investigate the reason.

Experience does not err. Only your judgments err by expecting from her what is not in her power.

Poor is the pupil who does not surpass his master.

Tears come from the heart and not from the brain.

While I thought that I was learning how to live, I have been learning how to die.

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

Our life is made by the death of others.

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.

Science is the captain, and practice the soldiers.

Why does the eye see a thing more clearly in dreams than the imagination when awake?

Intellectual passion drives out sensuality.

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.

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.

All our knowledge has its origins in our perceptions.

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.

The natural desire of good men is knowledge.

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.

Knowledge of the past and of the places of the earth is the ornament and food of the mind of man.

In order to arrive at knowledge of the motions of birds in the air, it is first necessary to acquire knowledge of the winds, which we will prove by the motions of water in itself, and this knowledge will be a step enabling us to arrive at the knowledge of beings that fly between the air and the wind.

In rivers, the water that you touch is the last of what has passed and the first of that which comes; so with present time.

Time abides long enough for those who make use of it.

For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return.

Marriage is like putting your hand into a bag of snakes in the hope of pulling out an eel.

It's easier to resist at the beginning than at the end.

Water is the driving force of all nature.

To such an extent does nature delight and abound in variety that among her trees there is not one plant to be found which is exactly like another; and not only among the plants, but among the boughs, the leaves and the fruits, you will not find one which is exactly similar to another.

Nature never breaks her own laws.

Nothing strengthens authority so much as silence.

The greatest deception men suffer is from their own opinions.

Men of lofty genius when they are doing the least work are most active.

Beyond a doubt truth bears the same relation to falsehood as light to darkness.

Learning never exhausts the mind.

The noblest pleasure is the joy of understanding.

The smallest feline is a masterpiece.

Life well spent is long.

Just as food eaten without appetite is a tedious nourishment, so does study without zeal damage the memory by not assimilating what it absorbs.