In one letter, she wrote: "You are unbearable and burdensome, and very hard to live with; all your good qualities are overshadowed by your conceit, and made useless to the world simply because you cannot restrain your propensity to pick holes in other people.

[16]: 25  In their youthful correspondence Arthur and Anthime were somewhat boastful and competitive about their sexual exploits—but Schopenhauer seemed aware that women usually did not find him very charming or physically attractive, and his desires often remained unfulfilled.

[16]: 141–144  He studied metaphysics, psychology and logic under Gottlob Ernst Schulze, the author of Aenesidemus, who made a strong impression and advised him to concentrate on Plato and Immanuel Kant.

His friends included Friedrich Gotthilf Osann, Karl Witte, Christian Charles Josias von Bunsen, and William Backhouse Astor Sr.[16]: 151 He arrived at the newly founded University of Berlin for the winter semester of 1811–12.

[16]: 179  He returned to Weimar but left after less than a month, disgusted by the fact that his mother was now living with her supposed lover, Georg Friedrich Konrad Ludwig Müller von Gerstenbergk [de], a civil servant twelve years younger than her; he considered the relationship an act of infidelity to his father's memory.

Schopenhauer was immediately impressed by the Upanishads (he called them "the production of the highest human wisdom", and believed that they contained superhuman concepts) and the Buddha,[25] and put them on a par with Plato and Kant.

[16]: 285–289 In September 1818, while waiting for his book to be published and conveniently escaping an affair with a maid that caused an unwanted pregnancy,[16]: 342  Schopenhauer left Dresden for a year-long vacation in Italy.

[16]: 350  He spent the winter months in Rome, where he accidentally met his acquaintance Karl Witte and engaged in numerous quarrels with German tourists in the Caffè Greco, among them Johann Friedrich Böhmer, who also mentioned his insulting remarks and unpleasant character.

[16]: 517  As Young Hegelians were advocating change and progress, Schopenhauer claimed that misery is natural for humans and that, even if some utopian society were established, people would still fight each other out of boredom, or would starve due to overpopulation.

[16]: 525  His private notes and correspondence show that he acknowledged some of the criticisms regarding contradictions, inconsistencies, and vagueness in his philosophy, but claimed that he was not concerned about harmony and agreement in his propositions[16]: 394  and that some of his ideas should not be taken literally but instead as metaphors.

In the spring of 1860 his health began to decline, and he experienced shortness of breath and heart palpitations; in September he suffered inflammation of the lungs and, although he was starting to recover, he remained very weak.

Writing shortly before the discovery of hyperbolic geometry demonstrated the logical independence of the axiom—and long before the general theory of relativity revealed that it does not necessarily express a property of physical space—Schopenhauer criticized mathematicians for trying to use indirect concepts to prove what he held was directly evident from intuitive perception.

The Euclidean method of demonstration has brought forth from its own womb its most striking parody and caricature in the famous controversy over the theory of parallels, and in the attempts, repeated every year, to prove the eleventh axiom (also known as the fifth postulate).

If we take a man who suffers when he sees his fellow men living in poverty and consequently uses a significant part of his income to support their needs instead of his own pleasures, then the simplest way to describe this is that he makes less distinction between himself and others than is usually made.

[64] Those who have experienced this intuitive knowledge cannot affirm life, but exhibit asceticism and quietism, meaning that they are no longer sensitive to motives, are not concerned about their individual welfare, and accept without resistance the evil that others inflict on them.

So much agreement in the case of such different ages and nations is a practical proof that what is expressed here is not, as optimistic dullness likes to assert, an eccentricity and perversity of the mind, but an essential side of human nature, which only appears so rarely because of its excellence.

[69] Schopenhauer's politics were an echo of his system of ethics, which he elucidated in detail in his Die beiden Grundprobleme der Ethik (the two essays On the Freedom of the Will and On the Basis of Morality).

He saw this as opposed to the ignorant drive toward earthly utopianism and superficiality of a worldly "Jewish" spirit: [Judaism] is, therefore, the crudest and poorest of all religions and consists merely in an absurd and revolting theism.

It amounts to this that the κύριος ['Lord'], who has created the world, desires to be worshipped and adored; and so above all he is jealous, is envious of his colleagues, of all the other gods; if sacrifices are made to them he is furious and his Jews have a bad time ...

[82] When the elderly Schopenhauer sat for a sculpture portrait by the Prussian sculptor Elisabet Ney in 1859, he was much impressed by the young woman's wit and independence, as well as by her skill as a visual artist.

Here Schopenhauer wrote: With our knowledge of the complete unalterability both of character and of mental faculties, we are led to the view that a real and thorough improvement of the human race might be reached not so much from outside as from within, not so much by theory and instruction as rather by the path of generation.

Schopenhauer considered India as "the land of the most ancient and most pristine wisdom, the place from which Europeans could trace their descent and the tradition by which they had been influenced in so many decisive ways",[103] and regarded the Upanishads as "the most profitable and elevating reading which [...] is possible in the world.

There, in almost every page this profound doctrine lies enshrined; with tireless repetition, in countless adaptations, by many varied parables and similes it is expounded and inculcated.For Schopenhauer, will had ontological primacy over the intellect; desire is prior to thought.

[111] Schopenhauer made the following statement in his discussion of religions:[112] If I wished to take the results of my philosophy as the standard of truth, I should have to concede to Buddhism pre-eminence over the others.

If Goethe had not been sent into the world simultaneously with Kant in order to counterbalance him, so to speak, in the spirit of the age, the latter would have been haunted like a nightmare many an aspiring mind and would have oppressed it with great affliction.

Bruno on the other hand, who knew much about nature and ancient literature, presented his ideas with Italian vividness, and is amongst philosophers the only one who comes near Plato's poetic and dramatic power of exposition.

[128] It is yet even more remarkable that Schopenhauer mentions Spinoza as an example of the denial of the will, if one uses the French biography by Jean Maximilien Lucas[129] as the key to Tractatus de Intellectus Emendatione.

The following passage is an example: All this explains the painful impression with which we are seized when, after studying genuine thinkers, we come to the writings of Fichte and Schelling, or even to the presumptuously scribbled nonsense of Hegel, produced as it was with a boundless, though justified, confidence in German stupidity.

[155] Jorge Luis Borges remarked that the reason he had never attempted to write a systematic account of his world view, despite his penchant for philosophy and metaphysics in particular, was because Schopenhauer had already written it for him.

[167] Advocates of idealism in contemporary analytic philosophy and neuroscience such as Bernardo Kastrup and Christof Koch owe their philosophical system, in part, to the metaphysics of Schopenhauer.