Mathemata mathematicis scribuntur Mathematics is written for mathematicians De Revolutionibus

To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.

Every light has its shadow, and every shadow hath a succeeding morning.

Of all things visible, the highest is the heaven of the fixed stars.

For I am not so enamoured of my own opinions that I disregard what others may think of them.

The Universe, wrought for us by a supremely good and orderly Creator.

Nations are not ruined by one act of violence, but gradually and in an almost imperceptible manner by the depreciation of their circulating currency, through its excessive quantity.

Finally we shall place the Sun himself at the center of the Universe.

Those things which I am saying now may be obscure, yet they will be made clearer in their proper place.

The massive bulk of the earth does indeed shrink to insignificance in comparison with the size of the heavens.

Mathematics is written for mathematicians.

A traitor commits his crime but once. The rest/is retribution.

Joblessness is a blessing

it feels nice to know about things and about oneself.

At its best, leadership development is not an “event.” It’s a capacity-building endeavor. It’s a process of human growth and development.

People's fantasies are what give them problems. If you didn't have fantasies you wouldn't have problems because you'd just take whatever was there.

My home was in a pleasant place outside of Philadelphia. But I really lived, truly lived, somewhere else. I lived within the covers of books.

The most fruitful and worthwhile thing I have ever done has been to teach.

Rules with an iron fist, but sometimes in that fist is a rose.

It's an honor for me to have the opportunity to work with Emilio Estefan.

Walking is the natural recreation for a man who desires not absolutely to suppress his intellect but to turn it out to play for a season.