Nietzsche wrote in the 19th century; his influence on 20th century European philosophy is enormous. He was a brilliant thinker, and had a prophetic perspective on the cataclysmic changes that were coming to Europe in the 20th century. His expertise was ancient philosophy. he was also a philosopher of religion, and wrote the famous parable “God is dead.” Here is how the Stanford Encyclopedia for Philosophy describes him:
“Friedrich Nietzsche (1844–1900) was a German philosopher of the late 19th century who challenged the foundations of Christianity and traditional morality. He was interested in the enhancement of individual and cultural health, and believed in life, creativity, power, and the realities of the world we live in, rather than those situated in a world beyond. Central to his philosophy is the idea of “life-affirmation,” which involves an honest questioning of all doctrines that drain life’s expansive energies, however socially prevalent those views might be. Often referred to as one of the first existentialist philosophers along with Søren Kierkegaard (1813–1855), Nietzsche’s revitalizing philosophy has inspired leading figures in all walks of cultural life, including dancers, poets, novelists, painters, psychologists, philosophers, sociologists and social revolutionaries.”
I have collected a few texts, and you can also find some German texts and poems by him on this site.
Origins of Knowledge
Throughout immense stretches of time the intellect produced nothing but errors; some of them proved to be useful and preservative of the species: he who fell in with them, or inherited them, waged the battle for himself and his offspring with better success. Those erroneous articles of faith which were successively transmitted by inheritance, and have finally become almost the property and stock of the human species, are, for example, the following: that there are enduring things, that there are equal things, that there are things, substances, and bodies, that a thing is what it appears, that our will is free that what is good for me is also good absolutely. It was only very late that the deniers, doubters of such propositions came forward – it was only very late that truth made its appearance as the most impotent form of knowledge. It seemed as if it were impossible to get along with truth, our organism was adapted for the very opposite; all its higher functions, the perceptions of the senses, and in general every kind of sensation, cooperated with those primevally embodied, fundamental errors. Moreover, those propositions became the very standards of knowledge according to which the “true “and the “false” were determined – throughout the whole domain of pure logic. The strength of conceptions does not, therefore, depend on their degree of truth, but on their antiquity, their embodiment, their character as conditions of life. Where life and knowledge seemed to conflict, there has never been serious contention; denial and doubt have there been regarded as madness. The exceptional thinkers like the Eleatics, who, in spite of this, advanced and maintained the antitheses of the natural errors, believed that it was possible also to live these counterparts: it was they who devised the sage as the man of immutability, impersonality and universality of intuition, as one and all at the same time, with a special faculty for that reverse kind of knowledge; they were of the belief that their knowledge was at the same time the principle of life. To be able to affirm all this, however, they had to deceive themselves concerning their own condition: they had to attribute to themselves impersonality and unchanging permanence, they had to mistake the nature of the philosophic individual, deny the force of the impulses in cognition, and conceive of reason generally as an entirely free and self-originating activity; they kept their eyes shut to the fact that they also had reached their doctrines in contradiction to valid methods, or through their longing for repose or for exclusive possession or for domination. The subtler development of sincerity and of skepticism finally made these men impossible; their life also, and their judgments, turned out to be dependent on the primeval impulses and fundamental errors of all sentient beings. The subtler sincerity and skepticism arose wherever two antithetical maxims appeared to be applicable to life, because both of them were compatible with the fundamental errors; where, therefore, there could be contention concerning a higher or lower degree of utility for life; and likewise where new maxims proved to be, not necessarily useful, but at least not injurious, as expressions of an intellectual impulse to play a game that was like all games innocent and happy The human brain was gradually filled with such judgments and convictions; and in this tangled skein there arose ferment, strife and lust for power. Not only utility and delight, but every kind of impulse took part in the struggle for “truths”; the intellectual struggle became a business, an attraction, a calling, a duty, an honor; cognizing and striving for the true finally arranged themselves as needs among other needs. From that moment not only belief and conviction, but also examination, denial, distrust and contradiction became forces; all “evil “instincts were subordinated to knowledge, were placed in its service, and acquired the prestige of the permitted, the honored, the useful, and finally the appearance and innocence of the good. Knowledge thus became a portion of life itself, and as life it became a continually growing power; until finally the cognitions and those primeval, fundamental errors clashed with each other, both as life, both as power, both in the same man. The thinker is now the being in whom the impulse to truth and those life-preserving errors wage their first conflict, now that the impulse to truth has also proved itself to be a life-preserving power. In comparison with the importance of this conflict everything else is indifferent; the final question concerning the conditions of life is here raised, and the first attempt is here made to answer it by experiment. How far is truth susceptible of embodiment – that is the question, that is the experiment.
Origin of the Logical
Where has logic originated in men’s heads? Undoubtedly out of the illogical, the domain of which must originally have been immense. But numberless beings who reasoned otherwise than we do at present, perished; albeit that they may have come nearer to truth than we! Whoever, for example, could not discern the “like” often enough with regard to food, and with regard to animals dangerous to him, whoever, therefore, deduced too slowly, or was too circumspect in his deductions, had smaller probability of survival than he who in all similar cases immediately divined the equality. The preponderating inclination, however, to deal with the similar as the equal – an illogical inclination, for there is no thing equal in itself – first created the whole basis of logic. It was just so (in order that the conception of substance should originate, this being indispensable to logic, although in the strictest sense nothing actual corresponds to it) that for a long period the changing process in things had to be overlooked, and remain unperceived; the beings not seeing correctly had an advantage over those who saw everything “in flux.” In itself every high degree of circumspection in conclusions, every skeptical inclination, is a great danger to life. No living being might have been preserved unless the contrary inclination – to affirm rather than suspend judgment, to mistake and fabricate rather than wait, to assent rather than deny, to decide rather than be in the right – had been cultivated with extra ordinary assiduity. The course of logical thought and reasoning in our modern brain corresponds to a process and struggle of impulses, which singly and in themselves are all very illogical and unjust; we experience usually only the result of the struggle so rapidly and secretly does this primitive mechanism now operate in us.
Cause and Effect
We say it is “explanation “; but it is only in “description” that we are in advance of the older stages of knowledge and science. We describe better, we explain just as little as our predecessors. We have discovered a manifold succession where the naive man and investigator of older cultures saw only two things, “cause” and “effect,”as it was said; we have perfected the conception of becoming, but have not got a knowledge of what is above and behind the conception. The series of “causes” stands before us much more complete in every case; we conclude that this and that must first precede in order that that other may follow – but we have not grasped anything thereby. The peculiarity, for example, in every chemical process seems a “miracle,” the same as before, just like all locomotion; nobody has “explained” impulse. How could we ever explain? We operate only with things which do not exist, with lines, surfaces, bodies, atoms, divisible times, divisible spaces – how can explanation ever be possible when we first make everything a conception, our conception? It is sufficient to regard science as the exactest humanizing of things that is possible; we always learn to describe ourselves more accurately by describing things and their successions. Cause and effect: there is probably never any such duality; in fact there is a continuum before us, from which we isolate a few portions – just as we always observe a motion as isolated points, and therefore do not properly see it, but infer it. The abruptness with which many effects take place leads us into error; it is however only an abruptness for us. There is an infinite multitude of processes in that abrupt moment which escape us. An intellect which could see cause and effect as a continuum, which could see the flux of events not according to our mode of perception, as things arbitrarily separated and broken – would throw aside the conception of cause and effect, and would deny all conditionality.
Have you ever heard of the madman who on a bright morning lighted a lantern and ran to the market-place calling out unceasingly: “I seek God! I seek God!” As there were many people standing about who did not believe in God, he caused a great deal of amusement. Why? is he lost? said one. Has he strayed away like a child? said another. Or does he keep himself hidden? Is he afraid of us? Has he taken a sea voyage? Has he emigrated? – the people cried out laughingly, all in a hubbub. The insane man jumped into their midst and transfixed them with his glances. “Where is God gone?” he called out. “I mean to tell you! We have killed him, you and I! We are all his murderers! But how have we done it? How were we able to drink up the sea? Who gave us the sponge to wipe away the whole horizon? What did we do when we loosened this earth from its sun? Whither does it now move? Whither do we move? Away from all suns? Do we not dash on unceasingly? Backwards, sideways, forwards, in all directions? Is there still an above and below? Do we not stray, as through infinite nothingness? Does not empty space breathe upon us? Has it not become colder? Does not night come on continually, darker and darker? Shall we not have to light lanterns in the morning? Do we not hear the noise of the grave-diggers who are burying God? Do we not smell the divine putrefaction? – for even Gods putrefy! God is dead! God remains dead! And we have killed him! How shall we console ourselves, the most murderous of all murderers? The holiest and the mightiest that the world has hitherto possessed, has bled to death under our knife – who will wipe the blood from us? With what water could we cleanse ourselves? What lustrums, what sacred games shall we have to devise? Is not the magnitude of this deed too great for us? Shall we not ourselves have to become Gods, merely to seem worthy of it? There never was a greater event – and on account of it, all who are born after us belong to a higher history than any history hitherto!” Here the madman was silent and looked again at his hearers; they also were silent and looked at him in surprise. At last he threw his lantern on the ground, so that it broke in pieces and was extinguished. “I come too early,” e then said. “I am not yet at the right time. This prodigious event is still on its way, and is traveling – it has not yet reached men’s ears. Lightning and thunder need time, the light of the stars needs time, deeds need time, even after they are done, to be seen and heard. This deed is as yet further from them than the furthest star – and yet they have done it themselves!” It is further stated that the madman made his way into different churches on the same day, and there intoned his Requiem aeternam deo. When led out and called to account, he always gave the reply: “What are these churches now, if they are not the tombs and monuments of God?”
History of an Error
The true world, attainable to the sage, the pious man and the man of virtue, – he lives in it, he is it. (The most ancient form of the idea was relatively clever, simple, convincing. It was a paraphrase of the proposition “I, Plato, am the truth.“)
The true world which is unattainable for the moment, is promised to the sage, to the pious man and to the man of virtue (”to the sinner who repents”). (Progress of the idea: it becomes more subtle, more insidious, more evasive, – it becomes a woman, it becomes Christian.)
The true world is unattainable, it cannot be proved, it cannot promise anything; but even as a thought, alone, it is a comfort, an obligation, a command. (At bottom this is still the old sun; but seen through mist and skepticism: the idea has become sublime, pale, northern, Königsbergian.)
The true world – is it unattainable? At all events it is unattained. And as unattained it is also unknown. Consequently it no longer comforts, nor saves, nor constrains: what could something unknown constrain us to? (The grey of dawn. Reason stretches itself and yawns for the first time. The cock-crow of positivism.)
The ”true world” – an idea that no longer serves any purpose, that no longer constrains one to anything, – a useless idea that has become quite superfluous, consequently an exploded idea: let us abolish it! (Bright daylight; breakfast; the return of common sense and of cheerfulness; Plato blushes for shame and all free-spirits kick up a shindy.)
We have suppressed the true world: what world survives? The apparent world perhaps? …Certainly not! In abolishing the true world we have also abolished the world of appearance!
(Noon; moment of the shortest shadows; end of the longest error; man-kind’s zenith; Incipit Zarathustra.)”
 Kant was a native of Königsberg and lived there all his life.
 Nietzsche, Twilight of the Idols, in: Complete Works, Russell & Russell, New York, 1964, Vol. 16, p. 24