“Art is a kind of innate drive that seizes a human being and makes him its instrument. To perform this difficult office it is sometimes necessary for him to sacrifice happiness and everything that makes life worth living for the ordinary human being.”

38a
Variant translations:
(More closely) The unexamining life is not worth living for a human being
The life which is unexamined is not worth living.
An unexamined life is not worth living.
The unexamined life is not the life for man.
Life without enquiry is not worth living for a man.<!--Translated by W. H. D. Rouse-->
Plato, Apology

Source: The Essential Drucker

Tragedy vs Evil (5th Biennial International Conference on Personal Meaning, July 24-27, 2008). https://www.youtube.com/watch?v=MLp7vWB0TeY&t=32m21s
Other

Criterion Collection essay on Rashamon, excerpted from Something Like an Autobiography as translated by Audie E. Bock (1982) http://www.criterion.com/current/posts/196-akira-kurosawa-on-rashomon
Context: Human beings are unable to be honest with themselves about themselves. They cannot talk about themselves without embellishing. This script portrays such human beings — the kind who cannot survive without lies to make them feel they are better people than they really are. It even shows this sinful need for flattering falsehood going beyond the grave — even the character who dies cannot give up his lies when he speaks to the living through a medium. Egoism is a sin the human being carries with him from birth; it is the most difficult to redeem. This film is like a strange picture scroll that is unrolled and displayed by the ego. You say that you can’t understand this script at all, but that is because the human heart itself is impossible to understand. If you focus on the impossibility of truly understanding human psychology and read the script one more time, I think you will grasp the point of it.

Complex (24 January 2012)

Speech at Southport, June 22, 1915. Quoted in The New York Times Current History, Volume 2; Volume 4. New York Times Company, 1917. Also quoted in Paul Piazza, Christopher Isherwood: Myth and Anti-Myth. Columbia Univesity Press, 2010 (p.217).

Ibid., p. 26.
The Gist of Art (1939)

Source: Simone Weil : An Anthology (1986), Analysis of Oppression (1955), p. 141
Context: The common run of moralists complain that man is moved by his private self-interest: would to heaven it were so! Private interest is a self-centered principle of action, but at the same time restricted, reasonable and incapable of giving rise to unlimited evils. Whereas, on the other hand, the law of all activities governing social life, except in the case of primitive communities, is that here one sacrifices human life — in himself and in others — to things which are only means to a better way of living. This sacrifice takes on various forms, but it all comes back to the question of power. Power, by definition, is only a means; or to put it better, to possess a power is simply to possess means of action which exceed the very limited force that a single individual has at his disposal. But power-seeking, owing to its essential incapacity to seize hold of its object, rules out all consideration of an end, and finally comes, through an inevitable reversal, to take the place of all ends. It is this reversal of the relationship between means and end, it is this fundamental folly that accounts for all that is senseless and bloody right through history. Human history is simply the history of the servitude which makes men — oppressed and oppressors alike — the plaything of the instruments of domination they themselves have manufactured, and thus reduces living humanity to being the chattel of inanimate chattels.

Source: The Moon is a Harsh Mistress