“There are some things that no amount of pure intelligence can anticipate, but which can only be learned by bitter experience.”

Ideology and Utopia (1929)

Source: The Negro (1915), Ch. XI: The Negro in the United States

In an interview for the George C. Marshall Institute http://www.marshall.org/article.php?id=21 (3 September 1997)

Source: After Dark

[IndieLondon, Donkey Punch - Olly Blackburn interview, http://www.indielondon.co.uk/Film-Review/donkey-punch-olly-blackburn-interview, www.indielondon.co.uk, 23 February 2012, 2008]

Variant, from Preface to Max Planck's Where is Science Going? (1933): The supreme task of the physicist is the discovery of the most general elementary laws from which the world-picture can be deduced logically. But there is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance, and this Einfühlung [literally, empathy or 'feeling one's way in']' is developed by experience.
1910s, Principles of Research (1918)
Context: The supreme task of the physicist is to arrive at those universal elementary laws from which the cosmos can be built up by pure deduction. There is no logical path to these laws; only intuition, resting on sympathetic understanding of experience, can reach them. In this methodological uncertainty, one might suppose that there were any number of possible systems of theoretical physics all equally well justified; and this opinion is no doubt correct, theoretically. But the development of physics has shown that at any given moment, out of all conceivable constructions, a single one has always proved itself decidedly superior to all the rest.

Source: Nature of Man and His Government (1959), p. 81

Tripadis