“They can because they think they can.”

Source: Aeneid (29–19 BC), Book V, Line 231 (tr. John Conington)

On why he chose to override engineers who thought the iMac wasn't feasible, as quoted in TIME magazine (24 October 2005)
2000s

Message to Linux kernel mailing list, 2006-09-22, Torvalds, Linus, 2008-06-07 http://lkml.org/lkml/2006/9/22/319,
2000s, 2006

Les espèces sont choisies non commes bonnes à manger, mais comme bonnes à penser.
Totemism (1962), [Le Totémisme aujourd'hui, as translated by Rodney Needham], p. 89
Often paraphrased as "Animals are good to think with".

Source: Ten Things We Did

Dilbert blog, My day as a Neanderthal, 2006-10-25, http://web.archive.org/20061107115218/dilbertblog.typepad.com/the_dilbert_blog/2006/10/my_day_as_a_nea.html, 2006-11-07 http://dilbertblog.typepad.com/the_dilbert_blog/2006/10/my_day_as_a_nea.html,

Fab. LII: Of the Forrester, the Skinner, and a Bear, Moral
The Fables of Aesop (2nd ed. 1668)