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.

So blind is the curiosity by which mortals are possessed, that they often conduct their minds along unexplored routes, having no reason to hope for success, but merely being willing to risk the experiment of finding whether the truth they seek lies there.

Even if I were to suppose that I was dreaming and whatever I saw or imagined was false, yet I could not deny that ideas were truly in my mind.

Even the mind depends so much on temperament and the disposition of one's bodily organs that, if it is possible to find a way to make people generally more wise and more skilful than they have been in the past, I believe that we should look for it in medicine. It is true that medicine as it is currently practiced contains little of much use.

I should consider that I know nothing about physics if I were able to explain only how things might be, and were unable to demonstrate that they could not be otherwise.

Except our own thoughts, there is nothing absolutely in our power.

Good sense is the most equitably distributed of all things because no matter how much or little a person has, everyone feels so abundantly provided with good sense that he feels no desire for more than he already possesses.