“There is another meaning that might be attached to this admonition to be oneself; that one should not try to disguise himself. I suspect this comes nearer to what psychologists mean when they urge people to be themselves. It is presumed that the person who faces the world barefaced is more spontaneous, that he expresses himself more fully, and that he has a better chance of developing all his resources if he assumes no disguises.
But this doctrine of psychological nakedness in human affairs, so much talked about today and which allows the self neither make-up nor costume, leaves very little to the imagination. Not does it invite one to be venturesome. I suspect, for example, that in the Garden of Eden it might have occurred to Adam to take a chance much sooner than he did if Eve had been paying a little more attention to her wardrobe. As it was I hear she had to bribe him with an apple. Later on they say she contrived a saucy little something out of fig leaves.”

Source: Man's Search for Meaning

1950's, On Being a Graphic Artist', 1953

"On Invisibility" in Diary of an Unknown (1953)

Source: Escape from Freedom (1941), Ch. 7, p. 262-3

Source: Path of Life (1909), p. 110

"The Contest in America," Fraser’s Magazine (February 1862); later published in Dissertations and Discussions (1868), vol.1 p. 26
Context: War is an ugly thing, but not the ugliest of things: the decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth a war, is much worse. When a people are used as mere human instruments for firing cannon or thrusting bayonets, in the service and for the selfish purposes of a master, such war degrades a people. A war to protect other human beings against tyrannical injustice; a war to give victory to their own ideas of right and good, and which is their own war, carried on for an honest purpose by their free choice, — is often the means of their regeneration. A man who has nothing which he is willing to fight for, nothing which he cares more about than he does about his personal safety, is a miserable creature who has no chance of being free, unless made and kept so by the exertions of better men than himself. As long as justice and injustice have not terminated their ever-renewing fight for ascendancy in the affairs of mankind, human beings must be willing, when need is, to do battle for the one against the other.

Source: The Mind Parasites (1967), p. 170

Einen Menschen verstehen heißt also: auch er sein. Der geniale Mensch aber offenbarte sich an jenen Beispielen eben als der Mensch, welcher ungleich mehr Wesen versteht als der mittelmäßige. Goethe soll von sich gesagt haben, es gebe kein Laster und kein Verbrechen, zu dem er nicht die Anlage in sich verspürt, das er nicht in irgend einem Zeitpunkte seines Lebens vollauf verstanden habe. Der geniale Mensch ist also komplizierter, zusammengesetzter, reicher; und ein Mensch ist um so genialer zu nennen, je mehr Menschen er in sich vereinigt, und zwar, wie hinzugefügt werden muß, je lebendiger, mit je größerer Intensität er die anderen Menschen in sich hat.
Source: Sex and Character (1903), p. 106.

"Real Charity"
What Buddhists Believe (1993)