“All natural capacities of a creature are destined to evolve completely to their natural end.”

De Generatione Animalium (1651)
Context: Man comes into the world naked and unarmed, as if nature had destined him for a social creature, and ordained him to live under equitable laws and in peace; as if she had desired that he should be guided by reason rather than be driven by force; therefore did she endow him with understanding, and furnish him with hands, that he might himself contrive what was necessary to his clothing and protection. To those animals to which nature has given vast strength, she has also presented weapons in harmony with their powers; to those that are not thus vigorous, she has given ingenuity, cunning, and singular dexterity in avoiding injury.

Second Thesis
Idea for a Universal History from a Cosmopolitan Point of View (1784)

Fourth Thesis
Idea for a Universal History from a Cosmopolitan Point of View (1784)

Source: The Limits of Evolution, and Other Essays, Illustrating the Metaphysical Theory of Personal Ideaalism (1905), The Art-Principle as Represented in Poetry, p.183-4

General Survey
The Function of the Orgasm (1927)
Context: Psychic health depends on orgastic potency, i. e., upon the degree to which one can surrender to and experience the climax of excitation in the natural sexual act. It is founded upon the healthy character attitude of the individual's capacity for love. Psychic illnesses are the result of a disturbance of the natural capacity for love.

As quoted in Carl Reinhold Bråkenhielm (2009), "Linnaeus and homo religiosus," Universitet, p. 83.

Preface To The 2011 edition, p. xi
The Expanding Circle: Ethics, Evolution, and Moral Progress (1981)

Ben Yamen's Song of Geometry (1853)
Context: Throughout nature the omnipresent beautiful revealed an all-pervading language spoken to the human mind, and to man's highest capacity of comprehension. By whom was it spoken? Whether by the gods of the ocean, or the land, by the ruling divinities of the sun, moon, and stars, or by the dryads of the forest and the nymphs of the fountain, it was one speech and its written cipher was cabalistic. The cabala were those of number, and even if they transcended the gemetricl skill of the Rabbi and the hieroglyphical learning of the priest of Osiris, they were, distinctly and unmistakably, expressions of thought uttered to mind by mind; they were the solutions of mathematical problems of extraordinary complexity.

Out of Control: The New Biology of Machines, Social Systems and the Economic World (1995)