On the one hand I have a clear and distinct idea of myself, in so far as I am a thinking, non-extended thing; and on the other hand I have a distinct idea of body, in so far a this is simply an extended, non-thinking thing. And, accordingly, it is certain that I am really distinct from my body, and exist without it.

It's the familiar love-hate syndrome of seduction: "I don't really care what it is I say, I care only that you like it."

Desire awakens only to things that are thought possible.

Science is practical philosophy.

With me, everything turns into mathematics.

Let whoever can do so deceive me, he will never bring it about that I am nothing, so long as I continue to think I am something.

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?