“Whatever is in common is true; but likeness is false. Trouillebert's work bears a likeness to that of Corot, but they have nothing in common.”

Cubism was born

Source: 1880's, Renoir – his life and work, 1975, p. 164 : quote from Renoir's letter to Durand-Ruell, 1882, referring to a small painting with trees of the landscape-painter Corot

Know Thyself (1881)
Context: What "Conservatives," "Liberals" and "Conservative-liberals," and finally "Democrats," "Socialists," or even "Social-democrats" etc., have lately uttered on the Jewish Question, must seem to us a trifle foolish; for none of these parties would think of testing that "Know thyself" upon themselves, not even the most indefinite and therefore the only one that styles itself in German, the "Progress"-party. There we see nothing but a clash of interests, whose object is common to all the disputants, common and ignoble: plainly the side most strongly organised, i. e. the most unscrupulous, will bear away the prize. With all our comprehensive State- and National-Economy, it would seem that we are victims to a dream now flattering, now terrifying, and finally asphyxiating: all are panting to awake therefrom; but it is the dream's peculiarity that, so long as it enmeshes us, we take it for real life, and fight against our wakening as though we fought with death. At last one crowning horror gives the tortured wretch the needful strength: he wakes, and what he held most real was but a figment of the dæmon of distraught mankind.
We who belong to none of all those parties, but seek our welfare solely in man's wakening to his simple hallowed dignity; we who are excluded from these parties as useless persons, and yet are sympathetically troubled for them, — we can only stand and watch the spasms of the dreamer, since no cry of ours can pierce to him. So let us save and tend and brace our best of forces, to bear a noble cordial to the sleeper when he wakes, as of himself he must at last.

Source: 1860s, Evidence as to Man's Place in Nature (1863), Ch.1, p. 34

VII, 53
Meditations (c. 121–180 AD), Book VII
Context: Where any work can be done conformably to the reason which is common to gods and men, there we have nothing to fear; for where we are able to get profit by means of the activity which is successful and proceeds according to our constitution, there no harm is to be suspected.

Emperor Has No Clothes Award acceptance speech (2003)
Context: Schizophrenics have a whole lot of trouble telling the level of abstraction of a story. They're always biased in the direction of interpreting things more concretely than is actually the case. You would take a schizopohrenic and say, "Okay, what do apples, bananas and oranges have in common?" and they would say, "They all are multi-syllabic words."
You say "Well, that's true. Do they have anything else in common?" and they say, "Yes, they actually all contain letters that form closed loops."
This is not seeing the trees instead of the forest, this is seeing the bark on the trees, this very concreteness.

In Search of the Miraculous (1949)
Context: When we speak of prayer or of the results of prayer we always imply only one kind of prayer — petition, or we think that petition can be united with all other kinds of prayers.… Most prayers have nothing in common with petitions. I speak of ancient prayers; many of them are much older than Christianity. These prayers are, so to speak, recapitulations; by repeating them aloud or to himself a man endeavors to experience what is in them, their whole content, with his mind and his feeling.

Stand Up

The Substitution of Similars, The True Principles of Reasoning (1869)
Context: Aristotle's dictim... may then be formulated somewhat as follows:—Whatever is known of a term may be stated of its equal or equivalent. Or, in other words, Whatever is true of a thing is true of its like.... the value of the formula must be judged by its results;... it not only brings into harmony all the branches of logical doctrine, but... unites them in close analogy to the corresponding parts of mathematical method. All acts of mathematical reasoning may... be considered but as applications of a corresponding axiom of quantity...