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

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.

Trouble springs from idleness, and grievous toil from needless ease.

We shall see but a little way if we require to understand what we see.