Human reason reduced to its own resources is perfectly worthless, not only for creating but also for preserving any political or religious association, because it only produces disputes, and, to conduct himself well, man needs not problems but beliefs. His cradle should be surrounded by dogmas, and when his reason is awakened, it should find all his opinions ready-made, at least all those relating to his conduct. Nothing is so important to him as prejudices.

The rights and duties of man thus simplified, it seems almost impertinent to attempt to illustrate truths that appear so incontrovertible: yet such deeply rooted prejudices have clouded reason, and such spurious qualities have assumed the name of virtues, that it is necessary to pursue the course of reason as it has been perplexed and involved in error, by various adventitious circumstances, comparing the simple axiom with casual deviations.
Men, in general, seem to employ their reason to justify prejudices, which they have imbibed, they cannot trace how, rather than to root them out. The mind must be strong that resolutely forms its own principles; for a kind of intellectual cowardice prevails which makes many men shrink from the task, or only do it by halves. Yet the imperfect conclusions thus drawn, are frequently very plausible, because they are built on partial experience, on just, though narrow, views.

There is no just cause for apprehending that we shall be misled by the proper exercise of reason on any subject which may be proposed for our consideration. The only danger is of making an improper use of this faculty, which is one of the most common faults to which our nature is liable. Most men profess that they are guided by reason in forming their opinions; but if this were really the case, the world would not be overrun with error; there would not be so many dangerous and absurd opinions propagated and pertinaciously defended.