God alone is the author of all the motions in the world.

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

Hence reason also demands that, since our thoughts cannot all be true because we are not wholly perfect, what truth they do possess must inevitably be found in the thoughts we have when awake, rather than in our dreams.

But possibly I am something more than I suppose myself to be.

Mathematics is a more powerful instrument of knowledge than any other that has been bequeathed to us by human agency.

Whatever I have up till now accepted as most true and assured I have gotten either from the senses or through the senses. But from time to time I have found that the senses deceive, and it is prudent never to trust completely those who have deceived us even once.

You just keep pushing. You just keep pushing. I made every mistake that could be made. But I just kept pushing.