
The Notebooks of Leonardo Da Vinci (1938), XXIX Precepts of the Painter
As quoted by Ludwig Boltzmann in a letter to Nature (28 February 1895) http://books.google.com/books?id=PnUCAAAAIAAJ
The Notebooks of Leonardo Da Vinci (1938), XXIX Precepts of the Painter
Letter to John Tyndall (19 April 1851); letter 2411, edited by
Context: I have far more confidence in the one man who works mentally and bodily at a matter than in the six who merely talk about it — and I therefore hope and am fully persuaded that you are working. Nature is our kindest friend and best critic in experimental science if we only allow her intimations to fall unbiased on our minds. Nothing is so good as an experiment which, whilst it sets an error right, gives us (as a reward for our humility in being reproved) an absolute advancement in knowledge.
Source: The Limits of Evolution, and Other Essays, Illustrating the Metaphysical Theory of Personal Ideaalism (1905), The Harmony of Determinism and Freedom, p.325
an act which it would be good to do, but not wrong not to do. On the contrary, we ought to give the money away, and it is wrong not to do so.
Famine, Affluence, and Morality http://www.utilitarian.net/singer/by/1972----.htm, 1972.
On seeing a 1956 performance by Billie Holiday, Talking to Myself Bk. 4 (1973) Ch. 4
Source: A Discourse on the Love of Our Country (1789), p. 11
Source: Kritik der zynischen Vernunft [Critique of Cynical Reason] (1983), p. 535