Satan, on the contrary, is thin, ascetic and a fanatical devotee of logic. He reads Machiavelli, Ignatius of Loyola, Marx and Hegel; he is cold and unmerciful to mankind, out of a kind of mathematical unmercifulness. He is damned always to do that which is most repugnant to him: to become a slaughterer, in order to abolish slaughtering, to sacrifice lambs so that no more lambs may be slaughtered, to whip people with knots so that they may learn not to let themselves be whipped, to strip himself of every scruple in the name of a higher scrupulousness, and to challenge the hatred of mankind because of his love for it--an abstract and geometric love.

— Arthur Koestler

Solitary confinement is rock bottom, it's an absolute freedom.

— Arthur Koestler

... The arbitrary power of the Government is unlimited, and unexampled in history; freedom of the Press, of opinion and of movement are as thoroughly exterminated as though the proclamation of the Rights of Man had never been.

— Arthur Koestler

The most persistent sound which reverberates through man's history is the beating of war drums.

— Arthur Koestler

The old disease, thought Basho. Revolutionaries should not think through other people's minds. Or, perhaps they should? Or even ought to? How can one change the world if one identifies oneself with everybody? How else can one change it? He who understands and forgives -- where would he find a motive to act? Where would he not?

— Arthur Koestler

The principal mark of genius is not perfection but originality, the opening of new frontiers.

— Arthur Koestler

The progress of science is strewn, like an ancient desert trail, with the bleached skeleton of discarded theories which once seemed to possess eternal life.

— Arthur Koestler

The ultimate truth is pen ultimately always a falsehood. He who will be proved right in the end appears to be wrong and harmful before it.

— Arthur Koestler

Wars are not fought for territory but for words. Man's deadliest weapon is language. He is as susceptible to being hypnotized by slogans as he is to infectious diseases. And where there is an epidemic the group-mind takes over.

— Arthur Koestler

When one contemplates the streak of insanity running through human history, it appears highly probable that Homo sapiens is a biological freak, the result of some remarkable mistake in the evolutionary process. The ancient doctrine of original sin, variants of which occur independently in the mythologies of diverse cultures, could be a reflection of man's awareness of his own inadequacy, of the intuitive hunch that somewhere along the line of his ascent something has gone wrong.

— Arthur Koestler