Diesen Ernsthaften diene zur Belehrung, dass ich von der Kunst als der höchsten Aufgabe und der eigentlich metaphysischen Thätigkeit dieses Lebens im Sinne des Mannes überzeugt bin, dem ich hier, als meinem erhabenen Vorkämpfer auf dieser Bahn, diese Schrift gewidmet haben will.
"Preface to Richard Wagner", p. 13
The Birth of Tragedy (1872)

“Our institutions are no good any more: on that there is universal agreement. However, it is not their fault but ours. Once we have lost all the instincts out of which institutions grow, we lose institutions altogether because we are no longer good for them.”

Friedrich Nietzsche book Twilight of the Idols

Twilight of the Idols (1888)

“Life and experience. If one notices how some individuals know how to treat their experiences (their insignificant everyday experiences) so that these become a plot of ground that bears fruit three times a year; while others (and how many of them!) are driven through the waves of the most exciting turns of fate, of the most varied currents of their time or nation, and yet always stay lightly on the surface, like cork: then one is finally tempted to divide mankind into a minority (minimality) of those people who know how to make much out of little and a majority of those who know how to make a little out of much; indeed, one meets those perverse wizards who, instead of creating the world out of nothing, create nothing out of the world.”

Friedrich Nietzsche book Human, All Too Human

Section IX, "Man Alone with Himself" / aphorism 627
Human, All Too Human (1878), Helen Zimmern translation

“I keep having the same experience and keep resisting it every time. I do not want to believe it although it is palpable: the great majority of people lack an intellectual conscience. Indeed, it has often seemed to me as if anyone calling for an intellectual conscience were as lonely in the most densely populated cities as if he were in a desert. Everybody looks at you with strange eyes and goes right on handling his scales, calling this good and that evil. Nobody even blushes when you intimate that their weights are underweight; nor do people feel outraged; they merely laugh at your doubts. I mean: the great majority of people does not consider it contemptible to believe this or that and to live accordingly, without first having given themselves an account of the final and most certain reasons pro and con, and without even troubling themselves about such reasons afterward: the most gifted men and the noblest women still belong to this "great majority." But what is goodheartedness, refinement, or genius to me, when the person who has these virtues tolerates slack feelings in his faith and judgments and when he does not account the desire for certainty as his inmost craving and deepest distress--as that which separates the higher human beings from the lower.”

Friedrich Nietzsche

Sec. 2
The Gay Science (1882)

“Meaning and morality of one's life come from within oneself. Healthy, strong individuals seek self-expansion by experimenting and by living dangerously. Life consists of an infinite number of possibilities, and the healthy person explores as many of them as possible. Religions that teach pity, self-contempt, humility, self-restraint and guilt are incorrect. The good life is ever-changing, challenging, devoid of regret, intense, creative, and risky.”

Friedrich Nietzsche

Attributed to Nietzsche on quotes sites and on social media, the original quotation is from An Introduction to the History of Psychology by B. R. Hergenhahn (2008, page 226) and is the author's summary of Nietzsche's ideas: "The meaning and morality of one's life come from within oneself. Healthy, strong individuals seek self-expansion by experimenting, by living dangerously. Life consists of an almost infinite number of possibilities, and the healthy person (the superman) explores as many of them as possible. Religions or philosophies that teach pity, humility, submissiveness, self-contempt, self-restraint, guilt, or a sense of community are simply incorrect. [...] For Nietzsche, the good life is ever-changing, challenging, devoid of regret, intense, creative, and risky."
Misattributed

“I call Christianity the one great curse, the one great intrinsic depravity, the one great instinct for revenge for which no expedient is sufficiently poisonous, secret, subterranean, petty — I call it the one immortal blemish of mankind.”

Friedrich Nietzsche book The Antichrist

Sec. 62
The Antichrist (1888)

“The man who does not wish to belong to the mass needs only to cease taking himself easily; let him follow his conscience, which calls to him: “Be your self! All you are now doing, thinking, desiring, is not you yourself.””

Friedrich Nietzsche Untimely Meditations

“Schopenhauer as educator,” § 3.1, R. Hollingdale, trans. (1983), p. 127
Untimely Meditations (1876)

“One will rarely err if extreme actions be ascribed to vanity, ordinary actions to habit, and mean actions to fear.”

Friedrich Nietzsche book Human, All Too Human

I.74
Human, All Too Human (1878)

“What follows, then? That one had better put on gloves before reading the New Testament. The presence of so much filth makes it very advisable. One would as little choose early Christians for companions as Polish Jews: not that one need seek out an objection to them — neither has a pleasant smell.”

Friedrich Nietzsche book The Antichrist

Sec. 46
The Antichrist (1888)

“If a temple is to be erected, a temple must be destroyed.”

Friedrich Nietzsche book On the Genealogy of Morality

Essay 2, Section 24
On the Genealogy of Morality (1887)

“Being silent is something one completely unlearns if, like him, one has been for so long a solitary mole - -”

Friedrich Nietzsche

Preface
Daybreak — Thoughts on the Prejudices of Morality (1881)

“There exists no more repulsive and desolate creature in the world than the man who has evaded his genius and who now looks furtively to left and right, behind him and all about him. In the end such a man becomes impossible to get hold of, since he is wholly exterior, without kernel: a tattered, painted bag of clothes; a decked-out ghost that cannot inspire even fear and certainly not pity.”

Friedrich Nietzsche Untimely Meditations

Es gibt kein öderes und widrigeres Geschöpf in der Natur als den Menschen, welcher seinem Genius ausgewichen ist und nun nach rechts und nach links, nach rückwärts und überallhin schielt. Man darf einen solchen Menschen zuletzt gar nicht mehr angreifen, denn er ist ganz Außenseite ohne Kern, ein anbrüchiges, gemaltes, aufgebauschtes Gewand.
“Schopenhauer as educator,” § 3.1, R. Hollingdale, trans. (1983), p. 128
Untimely Meditations (1876)

“Do not forget, man, consumed by lust:
you—are the stone, the desert, are death …”

Friedrich Nietzsche book Dionysian-Dithyrambs

Dionysian-Dithyrambs (1888)

“First principle: one must need to be strong — otherwise one will never become strong. — Those large hothouses [Treibhäuser] for the strong, for the strongest kind of human being that has ever been, the aristocratic commonwealths of the type of Rome or Venice, understood freedom exactly in the sense in which I understand the word freedom: as something one has and does not have, something one wants, something one conquers…”

Friedrich Nietzsche book Twilight of the Idols

Twilight of the Idols (1888)

“Let us face ourselves. We are Hyperboreans!”

Friedrich Nietzsche