We never understand a thing so well,and make it our own, as when we have discovered it for ourselves.

I concluded that I might take as a general rule the principle that all things which we very clearly and obviously conceive are true: only observing, however, that there is some difficulty in rightly determining the objects which we distinctly conceive.

Perfect numbers like perfect men are very rare.

There is a great difference between mind and body insomuch as body is by nature always divisible, and the mind is entirely indivisible.

Everything is self-evident.

I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.

Although my knowledge grows more and more, nevertheless I do not for that reason believe that it can ever be actually infinite, since it can never reach a point so high that it will be unable to attain any greater increase.