“Economists are surgeons ... who operate beautifully on the dead and torment the living.”

Section 124
The Passionate State Of Mind, and Other Aphorisms (1955)
Context: The sick in soul insist that it is humanity that is sick, and they are the surgeons to operate on it. They want to turn the world into a sickroom. And once they get humanity strapped to the operating table, they operate on it with an ax.

As quoted in news reports (18 March 1956) and Simpson's Contemporary Quotations (1988) by James Beasley Simpson

Source: Batman: The Dark Knight Returns

The Pageant of Life (1964), On Doctors

" My own heart let me have more have pity on http://www.bartleby.com/122/47.html", lines 1-4
Wessex Poems and Other Verses (1918)

Quoted, The Beautiful and Damned (1922)

On Literature, Revolution, Entropy and Other Matters (1923)
Context: It is an error to divide people into the living and the dead: there are people who are dead-alive, and people who are alive-alive. The dead-alive also write, walk, speak, act. But they make no mistakes; only machines make no mistakes, and they produce only dead things. The alive-alive are constantly in error, in search, in questions, in torment.
The same is true of what we write: it walks and it talks, but it can be dead-alive or alive-alive. What is truly alive stops before nothing and ceaselessly seeks answers to absurd, "childish" questions. Let the answers be wrong, let the philosophy be mistaken — errors are more valuable than truths: truth is of the machine, error is alive; truth reassures, error disturbs. And if answers be impossible of attainment, all the better! Dealing with answered questions is the privilege of brains constructed like a cow's stomach, which, as we know, is built to digest cud.

Source: Night-Thoughts (1742–1745), Night II, Line 24.