Nothing is more uncommon, than to see men consistent. Their opinions never influence their conduct except when conformable to their temperaments, passions, and interests. Daily experience shows, that religious opinions produce much evil and little good. They are hurtful, because they often favour the passions of tyrants, of ambitious men, of fanatics, and of priests; they are of no effect, because incapable of counter-balancing the present interests of the greater part of mankind. Religious principles are of no avail, when they act in opposition to ardent desires; though not unbelievers, men then conduct themselves as if they believed nothing.

We shall always be liable to err, when we judge of the opinions of men by their conduct, or of their conduct by their opinions. A religious man, notwithstanding the unsociable principles of a sanguinary religion, will sometimes by a happy inconsistency, be humane, tolerant, and moderate; the principles of his religion do not then agree with the gentleness of his character. Libertines, debauchees, hypocrites, adulterers, and rogues, often appear to have the best ideas upon morals. Why do they not reduce them to practice? Because their temperament, their interest, and their habits do not accord with their sublime theories. The rigid principles of Christian morality, which many people regard as divine, have but little influence upon the conduct of those, who preach them to others. Do they not daily tell us, to do what they preach, and not what they practise?

The partisans of Religion often denote an infidel by the word libertine. It is possible that many unbelievers may have loose morals, which is owing to their temperament, and not to their opinions. But how does their conduct affect their opinions? Cannot then an immoral man be a good physician, architect, geometrician, logician, or metaphysician? A man of irreproachable conduct may be extremely deficient in knowledge and reason. In quest of truth, it little concerns us from whom it comes. Let us not judge men by their opinions, nor opinions by men; let us judge men by their conduct, and their opinions by their conformity with experience and reason and by their utility to mankind.