“In what concerns you much, do not think that you have companions: know that you are alone in the world. ”

“I find it wholesome to be alone the greater part of the time. To be in company, even with the best, is soon wearisome and dissipating. I love to be alone. I never found the companion that was so companionable as solitude.”

“It is better to have your head in the clouds, and know where you are... than to breathe the clearer atmosphere below them, and think that you are in paradise.”

“Do not engage to find things as you think they are.”

“What people say you cannot do, you try and find that you can.”

“If you can speak what you will never hear, if you can write what you will never read, you have done rare things.”

“One is enough. If you are acquainted with the principle, what do you care for a myriad instances and applications?”