“Think, for a moment, of a cheetah, a sleek, beautiful animal, one of the fastest on earth, which roams freely on the savannas of Africa. In its natural habitat, it is a magnificent animal, almost a work of art, unsurpassed in speedor grace by any other animal. Now, think of a cheetah that has been captured and thrown into a miserable cage in a zoo. It has lost its original grace and beauty, and is put on display for our amusement. We see only the broken spirit of the cheetah in the cage, not its original power and elegance. The cheetah can be compared to the laws of physics, which are beautiful in their natural setting. The natural habitat of the laws of physics is higher-dimensional space-time. However, we can only measure the laws of physics when they have been broken and placed on display in a cage, which is our three-dimensional laboratory. We can only see the cheetah when its grace and beauty have been stripped away.”

Playboy, August 1972

Source: A Vindication of the Rights of Woman (1792), Ch. 3

Desmond Morris (2009), The Human Zoo, p. vii

Source: The Lives of the Painters, Sculptors, and Architects, 1900, p. 5

30 December 1850
Journal Intime (1882), Journal entries
Context: Each bud flowers but once and each flower has but its minute of perfect beauty; so, in the garden of the soul each feeling has, as it were, its flowering instant, its one and only moment of expansive grace and radiant kingship. Each star passes but once in the night through the meridian over our heads and shines there but an instant; so, in the heaven of the mind each thought touches its zenith but once, and in that moment all its brilliancy and all its greatness culminate. Artist, poet, or thinker, if you want to fix and immortalize your ideas or your feelings, seize them at this precise and fleeting moment, for it is their highest point. Before it, you have but vague outlines or dim presentiments of them. After it you will have only weakened reminiscence or powerless regret; that moment is the moment of your ideal.

Part 2, Section 12
A Treatise of Human Nature (1739-40), Book 2: Of the passions

Source: Letter to his daughter (1978), p. 63.
Context: Tin-pot dictators have ravaged Asia, Latin America and Africa. In the aftermath, they have done more to promote communism than the works of Marx and Engels, Lenin and Mao. They are the worst tyrants of the post-colonial period. They have destroyed time-honoured institutions and treated their people like animals. They have caused internal divisions and external confusion. The dictator is the one animal who needs to be caged. He betrays his profession and his constitution. He betrays the people and destroys human values. He destroys culture. He binds the youth. He makes the structure collapse. He rules by fluke and freak. He is the scourge and the ogre. He is a leper. Anyone who touches him also becomes a leper. He is the upstart who is devoid of ideals and ideology. Not a single one of them has made a moment's contribution to history.

Of the Origin and Progress of Language (Edinburgh and London: J. Balfour and T. Cadell, 2nd ed., 1774), Vol. I, Book II, Ch. II, pp. 224-225 https://archive.org/stream/originandprogre01conggoog#page/n251/mode/2up.

Emotional Architecture as Compared to Intellectual (1894)
Context: Man, by means of his physical power, his mechanical resources, his mental ingenuity, may set things side by side. A composition, literally so called, will result, but not a great art work, not at all an art work in fact, but merely a more or less refined exhibition of brute force exercised upon helpful materials. It may be as a noise in lessening degrees of offensiveness, it can never become a musical tone. Though it shall have ceased to be vulgar in becoming sophistical, it will remain to the end what it was in the beginning: impotent to inspire — dead, absolutely dead.
It cannot for a moment be doubted that an art work to be alive, to awaken us to its life, to inspire us sooner or later with its purpose, must indeed be animate with a soul, must have been breathed upon by the spirit and must breathe in turn that spirit. It must stand for the actual, vital first-hand experiences of the one who made it, and must represent his deep-down impression not only of physical nature but more especially and necessarily his understanding of the out-working of that Great Spirit which makes nature so intelligible to us that it ceases to be a phantasm and becomes a sweet, a superb, a convincing Reality.