Isaac Newton Quotes
A man may imagine things that are false, but he can only understand things that are true, for if the things be false, the apprehension of them is not understanding.
Newton, Isaac. Letter to Ignatius Pardies, 11 June 1672. The Correspondence of Isaac Newton, edited by H.W. Turnbull, vol. 1, Cambridge UP, 1959, p. 164.
This quote is sometime attributed to Niels Bohr. No definitive citation has been found.
Sir Isaac Newton PRS was an English mathematician, physicist, astronomer, theologian, and author (described in his time as a "natural philosopher") who is widely recognised as one of the greatest mathematicians and most influential scientists of all time and as a key figure in the scientific revolution. His book Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), first published in 1687, established classical mechanics. Newton also made seminal contributions to optics, and shares credit with Gottfried Wilhelm Leibniz for developing the infinitesimal calculus.