“In every remodelling of the present, the existing condition of things must be supplanted by a new one. Now every variety of circumstances in which men find themselves, every object which surrounds them, communicates a definite form and impress to their internal nature. This form is not such that it can change and adapt itself to any other a man may choose to receive; and the end is foiled, while the power is destroyed, when we attempt to impose upon that which is already stamped in the soul a form which disagrees with it.”

On naval timber and arboriculture (1831), Appendix F, part II

Book II, Ch. I, pp. 93-94.
Physics

Source: The Limits of State Action (1792), Ch. 16

Woman in the Nineteenth Century (1845)
Context: Every relation, every gradation of nature is incalculably precious, but only to the soul which is poised upon itself, and to whom no loss, no change, can bring dull discord, for it is in harmony with the central soul. If any individual live too much in relations, so that he becomes a stranger to the resources of his own nature, he falls, after a while, into a distraction, or imbecility, from which he can only becured by a time of isolation, which gives the renovating fountains time to rise up. With a society it is the same.

Source: Nationalism and Culture (1937), Ch. 1 "The Insufficiency of Economic Materialism"
Context: However fully man may recognise cosmic laws he will never be able to change them, because they are not his work. But every form of his social existence, every social institution which the past has bestowed on him as a legacy from remote ancestors, is the work of men and can be changed by human will and action or made to serve new ends. Only such an understanding is truly revolutionary and animated by the spirit of the coming ages. Whoever believes in the necessary sequence of all historical events sacrifices the future to the past. He explains the phenomena of social life, but he does not change them. In this respect all fatalism is alike, whether of a religious, political or economic nature. Whoever is caught in its snare is robbed thereby of life's most precious possession; the impulse to act according to his own needs. It is especially dangerous when fatalism appears in the gown of science, which nowadays so often replaces the cassock of the theologian; therefore we repeat: The causes which underlie the processes of social life have nothing in common with the laws of physical and mechanical natural events, for they are purely the results of human purpose, which is not explicable by scientific methods. To misinterpret this fact is a fatal self-deception from which only a confused notion of reality can result.

"Poets of the People" in Art, Literature and the Drama (1858).
Context: There are two modes of criticism. One which … crushes to earth without mercy all the humble buds of Phantasy, all the plants that, though green and fruitful, are also a prey to insects or have suffered by drouth. It weeds well the garden, and cannot believe the weed in its native soil may be a pretty, graceful plant.
There is another mode which enters into the natural history of every thing that breathes and lives, which believes no impulse to be entirely in vain, which scrutinizes circumstances, motive and object before it condemns, and believes there is a beauty in natural form, if its law and purpose be understood.

"The Irony of Liberalism"
Soliloquies in England and Later Soliloquies (1922)

"Communism. The Production of the Form of Intercourse Itself",
The Marx-Engels Reader
The German Ideology (1845/46)

Statement (1968) as quoted in Sathya Sai Speaks Volume VIII, p. 99f