Those who fear the facts will forever try to discredit the fact-finders.

There comes a moment during which almost every girl or boy falls into melancholy; they are tormented by a vague inquietude which rests on everything and finds nothing to calm it. They seek solitude; they weep; the silence to be found in cloister attracts them: the image of peace that seems to reign in religious houses seduces them. They mistake the first manifestations of a developing sexual nature for the voice of God calling them to Himself; and it is precisely when nature is inciting them that they embrace a fashion of life contrary to nature's wish.

The arbitrary rule of a just and enlightened prince is always bad. His virtues are the most dangerous and the surest form of seduction: they lull a people imperceptibly into the habit of loving, respecting, and serving his successor, whoever that successor may be, no matter how wicked or stupid.

The philosopher forms his principles on an infinity of particular observations. He does not confuse truth with plausibility, he takes for truth what is true, for false what is false, for doubtful what is doubtful, and probable what is probable. The philosophical spirit is thus a spirit of observation and accuracy.

There is no true sovereign except the nation; there can be no true legislator except the people.

It seems to me that if one had kept silence up to now regarding religion, people would still be submerged in the most grotesque and dangerous superstition ... regarding government, we would still be groaning under the bonds of feudal government ... regarding morals, we would still be having to learn what is virtue and what is vice. To forbid all these discussions, the only ones worthy of occupying a good mind, is to perpetuate the reign of ignorance and barbarism.

Integrity is the evidence of all civil virtues.