I Understood. I Have Understood.

If I Have Done The Public Any Service, It Is Due To My Patient Thought.

His Epitaph: Who, By Vigor Of Mind Almost Divine, The Motions And Figures Of The Planets, The Paths Of Comets, And The Tides Of The Seas First Demonstrated.

My Powers Are Ordinary. Only My Application Brings Me Success.

Where Both Are Friends, It Is Right To Prefer Truth.

I Do Not Feign Hypotheses.