“...if in the heat of the dispute he insists and asks, 'Am I not the master of throwing myself out of the window?' I shall answer him, no; that whilst he preserves his reason there is no probability that the desire of proving his free agency, will become a motive sufficiently powerful to make him sacrifice his life to the attempt: if, notwithstanding this, to prove he is a free agent, he should actually precipitate himself from the window, it would not be a sufficient warranty to conclude he acted freely, but rather that it was the violence of his temperament which spurred him on to this folly. Madness is a state, that depends upon the heat of the blood, not upon the will. A fanatic or a hero, braves death as necessarily as a more phlegmatic man or a coward flies from it.”

“Man’s life is a line that nature commands him to describe upon the surface of the earth, without his ever being able to swerve from it, even for an instant. He is born without his own consent; his organization does in nowise depend upon himself; his ideas come to him involuntarily; his habits are in the power of those who cause him to contract them; he is unceasingly modified by causes, whether visible or concealed, over which he has no control, which necessarily regulate his mode of existence, give the hue to his way of thinking, and determine his manner of acting. He is good or bad, happy or miserable, wise or foolish, reasonable or irrational, without his will being for any thing in these various states.”

“Man cannot cherish his existence any longer than life holds out charms to him: when he is wrought upon by painful sensations, or drawn by contrary impulsions, his natural tendency is deranged; he is under the necessity to follow a new route; this conducts him to his end, which it even displays to him as the most desirable good.”

“...if in the heat of the dispute he insists and asks, 'Am I not the master of throwing myself out of the window?' I shall answer him, no; that whilst he preserves his reason there is no probability that the desire of proving his free agency, will become a motive sufficiently powerful to make him sacrifice his life to the attempt: if, notwithstanding this, to prove he is a free agent, he should actually precipitate himself from the window, it would not be a sufficient warranty to conclude he acted freely, but rather that it was the violence of his temperament which spurred him on to this folly. Madness is a state, that depends upon the heat of the blood, not upon the will. A fanatic or a hero, braves death as necessarily as a more phlegmatic man or a coward flies from it.”

“Suns are extinguished or become corrupted, planets perish and scatter across the wastes of the sky; other suns are kindled, new planets formed to make their revolutions or describe new orbits, and man, an infinitely minute part of a globe which itself is only an imperceptible point in the immense whole, believes that the universe is made for himself.”

“Religion has ever filled the mind of man with darkness, and kept him in ignorance of his real duties and true interests. It is only by dispelling the clouds and phantoms of Religion, that we shall discover Truth, Reason, and Morality. Religion diverts us from the causes of evils, and from the remedies which nature prescribes; far from curing, it only aggravates, multiplies, and perpetuates them.”

“How could the human mind progress, while tormented with frightful phantoms, and guided by men, interested in perpetuating its ignorance and fears? Man has been forced to vegetate in his primitive stupidity: he has been taught stories about invisible powers upon whom his happiness was supposed to depend. Occupied solely by his fears, and by unintelligible reveries, he has always been at the mercy of priests, who have reserved to themselves the right of thinking for him, and of directing his actions.”

“It is thus religion infatuates man from his infancy, fills him with vanity and fanaticism: if he has a heated imagination it drives him on to fury; if he has activity, it makes him a madman, who is frequently as cruel to himself, as he is dangerous and incommodious to others: if, on the contrary, he be phlegmatic or of a slothful habit, he becomes melancholy and is useless to society.”

“When it shall be desired to enlighten man, let him always have truth laid before him. Instead of kindling his imagination by the idea of those pretended goods that a future state has in reserve for him, let him be solaced, let him be succoured; or, at least, let him be permitted to enjoy the fruit of his labour; let not his substance be ravaged from him by cruel imposts; let him not be discouraged from work, by finding all his labour inadequate to support his existence, let him not be driven into that idleness that will surely lead him on to crime: let him consider his present existence, without carrying his views to that which may attend him after his death: let his industry be excited; let his talents be rewarded; let him be rendered active, laborious, beneficent, and virtuous, in the world he inhabits; let it be shown to him that his actions are capable of having an influence over his fellow men, but not on those imaginary beings located in an ideal world.”

“Let education kindle only those which are truly beneficialto the human species; let it favour those alone which are really necessary to the maintenance of society. The passions of man are dangerous, only because every thing conspires to give them an evil direction.”

“If a faithful account was rendered of man's ideas upon the Divinity, he would be obliged to acknowledge, that for the most part the word Gods has been used to express the concealed, remote, unknown causes of the effects he witnessed; that he applies this term when the spring of natural, the source of known causes ceases to be visible: as soon as he loses the thread of these causes, or as soon as his mind can no longer follow the chain, he solves the difficulty, terminates his research, by ascribing it to his gods; thus giving a vague definition to an unknown cause, at which either his idleness, or his limited knowledge, obliges him to stop. When, therefore, he ascribes to his gods the production of some phenomenon, the novelty or the extent of which strikes him with wonder, but of which his ignorance precludes him from unravelling the true cause, or which he believes the natural powers with which he is acquainted are inadequate to bring forth; does he, in fact, do any thing more than substitute for the darkness of his own mind, a sound to which he has been accustomed to listen with reverential awe?”