“Political criticism is our enemies' best friend.”

Quoted in Miguel Helft, " Google and Salesforce Join to Fight Microsoft http://www.nytimes.com/2008/04/14/technology/14google.html?_r=1&oref=slogin", New York Times (April 14, 2008).

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.

The Concept of the Political (1927)

Diary of an Unknown (1988)

L'Opinion de ces Demoiselles, "Nos amis, nos ennemis" [Our friends, our enemies]. Expression used by the French during the truce after the capture of Sebastopol, referring to the Russians. Recorded in the London Times of that date. Reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 221.

The Concept of the Political (1927)

As quoted in Diogenes Laërtius, Lives and Opinions of Eminent Philosophers, "Pythagoras", Sect. 23, as translated in Dictionary of Quotations http://archive.org/details/dictionaryquota02harbgoog (1906) by Thomas Benfield Harbottle, p. 320

Source: Dark Skye