Reason is nothing without imagination.

What then is the source of my errors? They are owing simply to the fact that, since the will extends further than the intellect, I do not contain the will within the same boundaries; rather, I also extend it to things I do not understand. Because the will is indifferent in regard to such matters, it easily turns away from the true and the good; and in this way I am deceived and I sin.

I accept no principles of physics which are not also accepted in mathematics.

The principal effect of the passions is that they incite and persuade the mind to will the events for which they prepared the body.

At last I will devote myself sincerely and without reservation to the general demolition of my opinions.

In the matter of a difficult question it is more likely that the truth should have been discovered by the few than by the many.

Situations in life often permit no delay; and when we cannot determine the course which is certainly best, we must follow the one which is probably the best. This frame of mind freed me also from the repentance and remorse commonly felt by those vacillating individuals who are always seeking as worthwhile things which they later judge to be bad.