All the sciences have a relation, greater or less, to human nature; and...however wide any of them may seem to run from it, they still return back by one passage or another. Even Mathematics, Natural Philosophy, and Natural Religion, are in some measure dependent on the science of MAN; since they lie under the cognizance of men, and are judged of by their powers and faculties.

In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.

The bigotry of theologians is a malady which seems almost incurable.

All that belongs to human understanding, in this deep ignorance and obscurity, is to be sceptical, or at least cautious, and not to admit of any hypothesis whatever, much less of any which is supported by no appearance of probability.

Any person seasoned with a just sense of the imperfections of natural reason, will fly to revealed truth with the greatest avidity.

In public affairs men are often better pleased that the truth, though known to everybody, should be wrapped up under a decent cover than if it were exposed in open daylight to the eyes of all the world.

The life of man is of no greater importance to the universe than that of an oyster.