Albert Einstein: Doing

Variant: The world is dangerous, not because of those who do evil, but because of those who look on and do nothing.

Earliest published version found on Google Books with this phrasing is in the 1993 book The Internet Companion: A Beginner's Guide to Global Networking by Tracy L. LaQuey and Jeanne C. Ryer, p. 25 http://books.google.com/books?id=sP5SAAAAMAAJ&q=meowing#search_anchor. However, the quote seems to have been circulating on the internet earlier than this, appearing for example in this post from 1987 http://groups.google.com/group/comp.lang.c/msg/cc89abb5e065d23f?hl=en and this one from 1985 http://groups.google.com/group/net.sources.games/browse_thread/thread/846af15b5a38c35/3d6d5a639c24bba3. No reference has been found that cites a source in Einstein's original writings, and the quote appears to be a variation of an old joke that dates at least as far back as 1866, as discussed in this entry from the "Quote Investigator" blog http://quoteinvestigator.com/2012/02/24/telegraph-cat/#more-3387. A variant was told by Thomas Edison, appearing in The Diary and Sundry Observations of Thomas Alva Edison (1948), p. 216 http://books.google.com/books?id=NXtEAAAAIAAJ&q=edinburgh#search_anchor: "When I was a little boy, persistently trying to find out how the telegraph worked and why, the best explanation I ever got was from an old Scotch line repairer who said that if you had a dog like a dachshund long enough to reach from Edinburgh to London, if you pulled his tail in Edinburgh he would bark in London. I could understand that. But it was hard to get at what it was that went through the dog or over the wire." A variant of Edison's comment can be found in the 1910 book Edison, His Life and Inventions, Volume 1 by Frank Lewis Dyer and Thomas Commerford Martin, p. 53 http://books.google.com/books?id=qN83AAAAMAAJ&pg=PA53#v=onepage&q&f=false.
The wireless telegraph is not difficult to understand. The ordinary telegraph is like a very long cat. You pull the tail in New York, and it meows in Los Angles. The wireless is the same, only without the cat.
Variant, earliest known published version is How to Think Like Einstein by Scott Thorpe (2000), p. 61 http://books.google.com/books?id=9yrYQxBgIYEC&lpg=PP1&pg=PA61#v=onepage&q&f=false. Appeared on the internet before that, as in this archived page from 12 October 1999 http://web.archive.org/web/19991012152820/http://stripe.colorado.edu/%7Ejudy/einstein/advice.html
Misattributed

Variously attributed also to Benjamin Franklin and Mark Twain. The earliest known occurrence, and probable origin, is from a 1981 text from Narcotics Anonymous: "Insanity is repeating the same mistakes and expecting different results." Cf. Rita Mae Brown#Misattributed.
Misattributed
Variant: Insanity: doing the same thing over and over again and expecting different results.

Albert Einstein, as quoted by Virgil Henshaw in Albert Einstein: Philosopher Scientist (1949) edited by Paul A. Schilpp
1940s

1920s, Viereck interview (1929)

Letter to high school student Barbara Lee Wilson (7 January 1943), Einstein Archives 42-606
1940s

Variant translation: One of the strongest motives that lead men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one's own ever-shifting desires. A finely tempered nature longs to escape from the personal life into the world of objective perception and thought. With this negative motive goes a positive one. Man seeks to form for himself, in whatever manner is suitable for him, a simplified and lucid image of the world, and so to overcome the world of experience by striving to replace it to some extent by this image. This is what the painter does, and the poet, the speculative philosopher, the natural scientist, each in his own way. Into this image and its formation, he places the center of gravity of his emotional life, in order to attain the peace and serenity that he cannot find within the narrow confines of swirling personal experience.
As quoted in The Professor, the Institute, and DNA (1976) by Rene Dubos; also in The Great Influenza (2004) by John M. Barry
1910s, Principles of Research (1918)
Context: Man tries to make for himself in the fashion that suits him best a simplified and intelligible picture of the world; he then tries to some extent to substitute this cosmos of his for the world of experience, and thus to overcome it. This is what the painter, the poet, the speculative philosopher, and the natural scientist do, each in his own fashion. Each makes this cosmos and its construction the pivot of his emotional life, in order to find in this way the peace and security which he cannot find in the narrow whirlpool of personal experience.

1920s, Viereck interview (1929)
Context: But to return to the Jewish question. Other groups and nations cultivate their individual traditions. There is no reason why we should sacrifice ours. Standardization robs life of its spice. To deprive every ethnic group of its special traditions is to convert the world into a huge Ford plant. I believe in standardizing automobiles. I do not believe in standardizing human beings. Standardization is a great peril which threatens American culture.

Letter to Guy H. Raner Jr. (28 September 1949), from article by Michael R. Gilmore in Skeptic magazine, Vol. 5, No. 2 (1997)
1940s
Context: I have repeatedly said that in my opinion the idea of a personal God is a childlike one. You may call me an agnostic, but I do not share the crusading spirit of the professional atheist whose fervor is mostly due to a painful act of liberation from the fetters of religious indoctrination received in youth. I prefer an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our own being.

Answer to a survey written by the French mathematician Jaques Hadamard, from Hadamard's An Essay on the Psychology of Invention in the Mathematical Field (1945). Reprinted in Ideas and Opinions (1954). His full set of answers to the questions can be read on p. 3 here http://www.pitt.edu/~jdnorton/Goodies/Einstein_think/index.html.
1940s
Context: The words or the language, as they are written or spoken, do not seem to play any role in my mechanism of thought. The psychical entities which seem to serve as elements in thoughts are certain signs and more or less clear images which can be "voluntarily" reproduced and combined. There is, of course, a certain connection between those elements and relevant logical concepts. It is also clear that the desire to arrive finally at logically connected concepts is the emotional basis of this rather vague play with the above-mentioned elements.... The above-mentioned elements are, in my case, of visual and some muscular type. Conventional words or other signs have to be sought for laboriously only in a secondary stage, when the mentioned associative play is sufficiently established and can be reproduced at will.

Wording in Ideas and Opinions: Common to all these types is the anthropomorphic character of their conception of God. In general, only individuals of exceptional endowments, and exceptionally high-minded communities, rise to any considerable extent above this level. But there is a third stage of religious experience which belongs to all of them, even though it is rarely found in a pure form: I shall call it cosmic religious feeling. It is very difficult to elucidate this feeling to anyone who is entirely without it, especially as there is no anthropomorphic conception of God corresponding to it. The individual feels the futility of human desires and aims and the sublimity and marvelous order which reveal themselves both in nature and in the world of thought. Individual existence impresses him as a sort of prison and he wants to experience the universe as a single significant whole. The beginnings of cosmic religious feeling already appear at an early stage of development, e.g., in many of the Psalms of David and in some of the Prophets. Buddhism, as we have learned especially from the wonderful writings of Schopenhauer, contains a much stronger element of this. The religious geniuses of all ages have been distinguished by this kind of religious feeling, which knows no dogma and no God conceived in man's image; so that there can be no church whose central teachings are based on it. Hence it is precisely among the heretics of every age that we find men who were filled with this highest kind of religious feeling and were in many cases regarded by their contemporaries as atheists, sometimes also as saints. Looked at in this light, men like Democritus, Francis of Assisi, and Spinoza are closely akin to one another.
1930s, Religion and Science (1930)
Context: Common to all these types is the anthropomorphic character of the idea of God. Only exceptionally gifted individuals or especially noble communities rise essentially above this level; in these there is found a third level of religious experience, even if it is seldom found in a pure form. I will call it the cosmic religious sense. This is hard to make clear to those who do not experience it, since it does not involve an anthropomorphic idea of God; the individual feels the vanity of human desires and aims, and the nobility and marvelous order which are revealed in nature and in the world of thought. He feels the individual destiny as an imprisonment and seeks to experience the totality of existence as a unity full of significance. Indications of this cosmic religious sense can be found even on earlier levels of development—for example, in the Psalms of David and in the Prophets. The cosmic element is much stronger in Buddhism, as, in particular, Schopenhauer's magnificent essays have shown us. The religious geniuses of all times have been distinguished by this cosmic religious sense, which recognizes neither dogmas nor God made in man's image. Consequently there cannot be a church whose chief doctrines are based on the cosmic religious experience. It comes about, therefore, that we find precisely among the heretics of all ages men who were inspired by this highest religious experience; often they appeared to their contemporaries as atheists, but sometimes also as saints. Viewed from this angle, men like Democritus, Francis of Assisi, and Spinoza are near to one another.

Wording in Ideas and Opinions: Everything that the human race has done and thought is concerned with the satisfaction of deeply felt needs and the assuagement of pain. One has to keep this constantly in mind if one wishes to understand spiritual movements and their development. Feeling and longing are the motive force behind all human endeavor and human creation, in however exalted a guise the latter may present themselves to us.
1930s, Religion and Science (1930)
Context: Everything that men do or think concerns the satisfaction of the needs they feel or the escape from pain. This must be kept in mind when we seek to understand spiritual or intellectual movements and the way in which they develop. For feelings and longings are the motive forces of all human striving and productivity—however nobly these latter may display themselves to us.

Source: Attributed in posthumous publications, Einstein and the Poet (1983), p. 89
Context: The God Spinoza revered is my God, too: I meet Him everyday in the harmonious laws which govern the universe. My religion is cosmic, and my God is too universal to concern himself with the intentions of every human being. I do not accept a religion of fear; My God will not hold me responsible for the actions that necessity imposes. My God speaks to me through laws.

Insofern sich die Sätze der Mathematik auf die Wirklichkeit beziehen, sind sie nicht sicher, und insofern sie sicher sind, beziehen sie sich nicht auf die Wirklichkeit. http://books.google.com/books?id=QF0ON71WuxEC&q=%22Insofern+sich+die+S%C3%A4tze+der+Mathematik+auf+die%22&pg=PA3#v=onepage

Geometrie and Erfahrung (1921) pp. 3-4 link.springer.com http://link.springer.com/chapter/10.1007%2F978-3-642-49903-6_1#page-1 as cited by Karl Popper, The Two Fundamental Problems of the Theory of Knowledge (2014) Tr. Andreas Pickel, Ed. Troels Eggers Hansen.
Ref: en.wikiquote.org - Albert Einstein / Quotes / 1920s

http://books.google.com/books?id=QF0ON71WuxEC&q=%22beziehen+sind+sie+nicht+sicher+und+insofern+sie+sicher+sind+beziehen+sie+sich+nicht+auf+die+Wirklichkeit%22&pg=PA4#v=onepage
1920s, Sidelights on Relativity (1922)