Omnia apud me mathematica fiunt.

The entire method consists in the order and arrangement of the things to which the mind's eye must turn so that we can discover some truth.

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

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?

The two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge.

And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.

For I found myself embarrassed with so many doubts and errors that it seemed to me that the effort to instruct myself had no effect other than th eincreasing discovery of my own ignorance