Knowing Thyself, That Is The Greatest Wisdom.

Long Experience Has Taught Me This About The Status Of Mankind With Regard To Matters Requiring Thought: The Less People Know And Understand About Them, The More Positively They Attempt To Argue Concerning Them, While On The Other Hand To Know And Understand A Multitude Of Things Renders Men Cautious In Passing Judgment Upon Anything New.

I Do Not Feel Obliged To Believe That The Same God Who Has Endowed Us With Senses, Reason, And Intellect Has Intended Us To Forego Their Use.

It Reveals To Me The Causes Of Many Natural Phenomena That Are Entirely Incomprehensible In The Light Of The Generally Accepted Hypotheses. To Refute The Latter I Collected Many Proofs, But I Do Not Publish Them ... I Would Dare To Publish My Speculations If There Were People Men Like You.

The Laws Of Nature Are Written In The Language Of Mathematics...the Symbols Are Triangles, Circles And Other Geometrical Figures, Without Whose Help It Is Impossible To Comprehend A Single Word.

I Would Beg The Wise And Learned Fathers [of The Church] To Consider With All Diligence The Difference Which Exists Between Matters Of Mere Opinion And Matters Of Demonstration.