I know that I am intelligent, because I know that I know nothing.

I decided to sell my drawings. However, I didn't want people to buy my drawings because the professor of physics isn't supposed to be able to draw - isn't that wonderful - so I made up a false name.

It is a mania shared by philosophers of all ages to deny what exists and to explain what does not exist.

Many are they who have a taste and love for drawing, but no talent; and this will be discernible in boys who are not diligent and never finish their drawings with shading.

Nearly every man who develops an idea works it up to the point where it looks impossible, and then he gets discouraged. That's not the place to become discouraged.