So much barbarism, however, still remains in the transactions of most civilized nations, that almost all independent countries choose to assert their nationality by having, to their inconvenience and that of their neighbors, a peculiar currency of their own.

A population may be too crowded, though all be amply supplied with food and raiment. It is not good for a man to be kept perforce at all times in the presence of his species.

Truth gains more even by the errors of one who, with due study and preparation, thinks for himself, than by the true opinions of those who only hold them because they do not suffer themselves to think.

All free communities have both been more exempt from social injustice and crime, and have attained more brilliant prosperity, than any others, or than they themselves after they have lost their freedom.

The perpetual obstacle to human advancement is custom.

If two or more instances of the phenomenon under investigation have only one circumstance in common, the circumstance in which alone all the instances agree is the cause (or effect) of the given phenomenon.

Every established fact which is too bad to admit of any other defence is always presented to us as an injunction of religion.