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Voltaire : Limits of the human mind

Dernière mise à jour : 30 mai 2023

François-Marie Arouet, known as Voltaire

(1694 - 1778)

Extracts from:


Philosophical Dictionary



Someone asked Newton one day why he walked when he wanted to, and how his arm and his hand moved at his will. He answered manfully that he had no idea. "But at least," his interlocutor said to him, "you who understand so well the gravitation of the planets will tell me why they turn in one direction rather than in another!" And he again confessed that he had no idea. (...)

Has anyone ever been able to say precisely how a log is changed on the hearth into burning carbon, and by what mechanism lime is kindled by fresh water ?

Is the first principle of the movement of the heart in animals properly understood ? does one know clearly how generation is accomplished ? has one guessed what gives us sensations, ideas, memory ? We do not understand the essence of matter any more than the children who touch its surface.

Who will teach us by what mechanism this grain of wheat that we throw into the ground rises again to produce a pipe laden with an ear of corn, and how the same soil produces an apple at the top of this tree, and a chestnut on its neighbour ? Many teachers have said — "What do I not know ?" Montaigne used to say — "What do I know ?"

Ruthlessly trenchant fellow, wordy pedagogue, meddlesome theorist, you seek the limits of your mind. They are at the end of your nose.



I am ignorant of how I was formed, and of how I was born. For a quarter of my life I was absolutely ignorant of the reasons for all that I saw, heard and felt, and I was nothing but a parrot at whom other parrots chattered.


What is sensation ? How have I received it ? what connection is there between the air which strikes my ear and the sensation of sound ? between this body and the sensation of colour ? I am profoundly ignorant thereof, and I shall always be ignorant thereof.

What is thought ? where does it dwell ? how is it formed ? who gives me thought during my sleep? is it by virtue of my will that I think ? But always during my sleep, and often while I am awake, I have ideas in spite of myself. These ideas, long forgotten, long relegated to the back shop of my brain, issue from it without my interfering, and present themselves to my memory, which makes vain efforts to recall them.

External objects have not the power to form ideas in me, for one does not give oneself what one has not; I am too sensible that it is not I who give them to me, for they are born without my orders. Who produces them in me? whence do they come? whither do they go ? Fugitive phantoms, what invisible hand produces you and causes you to disappear ?

Why, alone of all animals, has man the mania for dominating his fellow-men ?

Why and how has it been possible that of a hundred thousand million men more than ninety-nine have been immolated to this mania ?

How is reason so precious a gift that we would not lose it for anything in the world ? and how has this reason served only to make us the most unhappy of all beings ?

Whence comes it that loving truth passionately, we are always betrayed to the most gross impostures ?

Why is life still loved by this crowd of Indians deceived and enslaved by the bonzes, crushed by a Tartar's descendants, overburdened with work, groaning in want, assailed by disease, exposed to every scourge ?

Whence comes evil, and why does evil exist ?

O atoms of a day ! O my companions in infinite littleness, born like me to suffer everything and to be ignorant of everything, are there enough madmen among you to believe that they know all these things ?

No, there are not; no, at the bottom of your hearts you feel your nonentity as I render justice to mine. But you are arrogant enough to want people to embrace your vain systems; unable to be tyrants over our bodies, you claim to be tyrants over our souls.



Philosopher, lover of wisdom, that is to say, of truth. All philosophers have had this dual character; there is not one in antiquity who has not given mankind examples of virtue and lessons in moral truths.


By what fatality, shameful maybe for the Western peoples, is it necessary to go to the far Orient to find a wise man who is simple, unostentatious, free from imposture, who taught men to live happily six hundred years before our vulgar era, at a time when the whole of the North was ignorant of the usage of letters, and when the Greeks were barely beginning to distinguish themselves by their wisdom ?

This wise man is Confucius, who being legislator never wanted to deceive men. What more beautiful rule of conduct has ever been given since him in the whole world ?

"Rule a state as you rule a family ; one can only govern one's family well by setting the example."

"Virtue should be common to both husbandman and monarch."

"Apply thyself to the trouble of preventing crimes in order to lessen the trouble of punishing them.

"Under the good kings Yao and Xu the Chinese were good; under the bad kings Kie and Chu they were wicked."

"Do to others as to thyself."

"Love all men; but cherish honest people. Forget injuries, and never kindnesses."

"I have seen men incapable of study; I have never seen them incapable of virtue."

Let us admit that there is no legislator who has proclaimed truths more useful to the human race.

A host of Greek philosophers have since taught an equally pure moral philosophy. If they had limited themselves to their empty systems of natural philosophy, their names would be pronounced today in mockery only. If they are still respected, it is because they were just, and that they taught men to be so."

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