Arthur Schopenhauer, The World as Will and Representation, Vol 1

"Boredom is certainly not an evil to be taken lightly: it will ultimately etch lines of true despair onto a face. It makes beings with as little love for each other as humans nonetheless seek each other with such intensity, and in this way becomes the source of sociability."

"Spinoza says that if a stone which has been projected through the air, had consciousness, it would believe that it was moving of its own free will. I add this only, that the stone would be right. The impulse given it is for the stone what the motive is for me, and what in the case of the stone appears as cohesion, gravitation, rigidity, is in its inner nature the same as that which I recognise in myself as will, and what the stone also, if knowledge were given to it, would recognise as will."

"[Materialism] seeks the primary and most simple state of matter, and then tries to develop all the others from it; ascending from mere mechanism, to chemism, to polarity, to the vegetable and to the animal kingdom. And if we suppose this to have been done, the last link in the chain would be animal sensibility - that is knowledge - which would consequently now appear as a mere modification or state of matter produced by causality. Now if we had followed materialism thus far with clear ideas, when we reached its highest point we would suddenly be seized with a fit of the inextinguishable laughter of the Olympians. As if waking from a dream, we would all at once become aware that its final result - knowledge, which it reached so laboriously, was presupposed as the indispensable condition of its very starting-point, mere matter; and when we imagined that we thought matter, we really thought only the subject that perceives matter; the eye that sees it, the hand that feels it, the understanding that knows it. Thus the tremendous petitio principii reveals itself unexpectedly."

"Every fulfilled wish we wrest from the world is really like alms that keep the beggar alive today so that he can starve again tomorrow."

"What give all that is tragic, whatever its form, the characteristic of the sublime, is the first inkling of the knowledge that the world and life can give no satisfaction, and are not worth our investment in them. The tragic spirit consists in this. Accordingly it leads to resignation."

"The life of every individual, viewed as a whole and in general, and when only its most significant features are emphasized, is really a tragedy; but gone through in detail it has the character of a comedy."

"For whence did Dante get the material for his hell, if not from this actual world of ours? And indeed he made a downright hell of it."

"What keeps all living things busy and in motion is the striving to exist. But when existence is secured, they do not know what to do: that is why the second thing that sets them in motion is a striving to get rid of the burden of existence, not to feel it any longer, 'to kill time', i.e. to escape boredom."

"Life is short and truth works far and lives long: let us speak the truth."

"optimism, where it is not just the thoughtless talk of someone with only words in his flat head, strikes me as not only absurd, but even a truly wicked way of thinking, a bitter mockery of the unspeakable sufferings of humanity."

"All striving comes from lack, from a dissatisfaction with one's condition, and is thus suffering as long as it is not satisfied; but no satisfaction is lasting; instead, it is only the beginning of a new striving. We see striving everywhere inhibited in many ways, struggling everywhere; and thus always suffering; there is no final goal of striving, and therefore no bounds or end to suffering."

"It is easy to understand that in the dreary middle ages the Aristotelian logic would be very acceptable to the controversial spirit of the schoolmen, which, in the absence of all real knowledge, spent its energy upon mere formulas and words, and that it would be eagerly adopted even in its mutilated Arabian form, and presently established as the centre of all knowledge."

"Death is the true inspiring genius, or the muse of philosophy, wherefore Socrates has defined the latter as θανάτου μελέτη. Indeed without death men would scarcely philosophise."

"Only by the aid of language does reason bring about its most important achievements, namely the harmonious and consistent action of several individuals, the planned cooperation of many thousands, civilization, the State; and then, science, the storing up of previous experience, the summarizing into one concept of what is common, the communication of truth, the spreading of error, thoughts and poems, dogmas and superstitions. The animal learns to know death only when he dies, but man consciously draws every hour nearer his death; and at times this makes life a precarious business, even to the man who has not already recognized this character of constant annihilation in the whole of life itself."