“To think? That’s it. It is thought. This alone cannot be detached from me. I am, I exist; that is certain.”

Am I so tied to a body and senses that I am incapable of existing without them?

Each problem that I solved became a rule which served afterwards to solve other problems.

The first precept was never to accept a thing as true until I knew it as such without a single doubt

Masked, I advance.

There is nothing more ancient than the truth.

When it is not in our power to determine what it true, we ought to follow what is most probable.

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 the increasing discovery of my own ignorance

All that is necessary to right action is right judgment, and to the best action the most correct judgment.

I desire to live in peace and to continue the life I have begun under the motto ‘to live well you must live unseen’.

Truths are more likely to have been discovered by one man than by nation

I doubt, therefore I think, therefore I am.

But what then am I? A thing that thinks. What is that? A thing that doubts, understand, affirms, denies, wills, refuses, and that also imagines and senses.

He who hid well, lived well.

Common sense is the most widely shared commodity in the world, for every man is convinced that he is well supplied with it.

One should never judge anything unless it is known

That we conduct our thoughts along different ways, and do not fix our attention on the same objects.

If we have white persons in the March, we are certain to have trouble with the Communists, and it may not be viewed as a true expression of the Negro’s protest.

I certainly would not like to end up in a tie-up with Ms. Rousey.

Are more sure when you can write, even more when you can teach, but certain when you can program.

There is a certain grandeur.

Some actors come to the set ready to do their parts a certain way.

Space is certainly something more complicated than the average person would probably realize.

It’s a life of sacrifice. There are rewards, but also a certain degree of sterility.

Drawing an object that has a certain amount of wear and tear or rust; or a tree that is damaged.