“Philosophy ... is a science, and as such has no articles of faith; accordingly, in it nothing can be assumed as existing except what is either positively given empirically, or demonstrated through indubitable conclusions.”

“Human life must be some kind of mistake. The truth of this will be sufficiently obvious if we only remember that man is a compound of needs and necessities hard to satisfy; and that even when they are satisfied, all he obtains is a state of painlessness, where nothing remains to him but abandonment to boredom. This is direct proof that existence has noreal value in itself; for what is boredom but the feeling of the emptiness of life? If life—the craving for which is the very essence of our being—were possessed of any positive intrinsic value, there would be no such thing as boredom at all: mere existence would satisfy us in itself, and we should want for nothing.”

“If life — the craving for which is the very essence of our being — were possessed of any positive intrinsic value, there would be no such thing as boredom at all: mere existence would satisfy us in itself, and we should want for nothing.”

“A book can never be anything more than the impress of its author's thoughts; and the value of these will lie either in the matter about which he has thought, or in the form which his thoughts take, in other words, what it is that he has thought about it.”

“You can do what you will, but in any given moment of your life you can will only one definite thing.”

“To free a man from error is not to deprive him of anything but to give him something: for the knowledge that a thing is false is a piece of truth. No error is harmless: sooner or later it will bring misfortune to him who harbours it. Therefore deceive no one, but rather confess ignorance of what you do not know, and leave each man to devise his own articles of faith for himself.”

“Science is not a taxi-cab that we can get in and out of whenever we like.”