For to be possessed of a vigorous mind is not enough; the prime requisite is rightly to apply it.

Divide each difficulty into as many parts as is feasible and necessary to resolve it.

The chief cause of human errors is to be found in the prejudices picked up in childhood.

He lives well who is well hidden.

Be that as it may, there is fixed in my mind a certain opinion of long standing, namely that there exists a God who is able to do anything and by whom I, such as I am, have been created. How do I know that he did not bring it about that there is no earth at all, no heavens, no extended thing, no shape, no size, no place, and yet bringing it about that all these things appear to me to exist precisely as they do now?

There is nothing so far removed from us as to be beyond our reach, or so hidden that we cannot discover it.

Good sense is, of all things among men, the most equally distributed; for every one thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.