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. – Nicolaus Copernicus
Not a few other very eminent and scholarly men made the same request, urging that I should no longer through fear refuse to give out my work for the common benefit of students of Mathematics. – Nicolaus Copernicus
For it is the duty of an astronomer to compose the history of the celestial motions through careful and expert study. – Nicolaus Copernicus
So far as hypotheses are concerned, let no one expect anything certain from astronomy, which cannot furnish it, lest he accept as the truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it. – Nicolaus Copernicus