“Poetry is an ethic. By ethic I mean a secret code of behavior, a discipline constructed and conducted according to the capabilities of a man who rejects the falsifications of the categorical imperative.”

Source: One-Dimensional Man (1964), p. 125

Source: The Bed of Procrustes: Philosophical and Practical Aphorisms (2010), p. 66

Individualism and Socialism (1933)

It will be objected: 'No! You are forgetting the active subject, the one that intervenes against barbarism!'So let us be precise: man is the being who is capable of recognzing himself as a victim.
Source: Ethics, Chapter One, Section III: "Man Living animal or immortal singularity?"

Source: Christianity and the Social Crisis (1907), Ch.1 The Historical Roots of Christianity the Hebrew Prophets, p. 7
Context: The prophets were the heralds of the fundamental truth that religion and ethics are inseparable, and that ethical conduct is the supreme and sufficient religious act. If that principle had been fully adopted in our religious life, it would have turned the full force of the religious impulse into the creation of right moral conduct and would have made the unchecked growth and accumulation of injustice impossible.

Source: Man’s Search for Himself (1953), p. 150
Context: Man is the "ethical animal" — ethical in potentiality even if, unfortunately, not in actuality. His capacity for ethical judgment — like freedom, reason and the other unique characteristics of the human being — is based upon his consciousness of himself.

Kulturphilosophie (1923), Vol. 2 : Civilization and Ethics
Context: I must interpret the life about me as I interpret the life that is my own. My life is full of meaning to me. The life around me must be full of significance to itself. If I am to expect others to respect my life, then I must respect the other life I see, however strange it may be to mine. And not only other human life, but all kinds of life: life above mine, if there be such life; life below mine, as I know it to exist. Ethics in our Western world has hitherto been largely limited to the relations of man to man. But that is a limited ethics. We need a boundless ethics which will include the animals also.

Quoted in "Bulletin" - Page 9 - History - 1962

"An Exposition of the Mission of England: Addressed to the Peoples of Europe" in The Reasoner, Vol. 3, No. 54 (1847), p. 321
Context: It is not, happily, within our power thus to work destruction in the universal womb of things; still within the sphere of human influence — which extends to the uttermost limit of our world's circumambient atmosphere — we can, and do, modify all nature's kingdom; bending towards good or ill, health or disease, harmony or discord, each part, each unit of the universal plan. Upon our just or erroneous comprehension then, of the laws of nature, must depend our adaptation of art for the right improvement or for the ignorant deterioration of Nature's works. And moreover, upon our just or erroneous interpretation of these in the first division of truth — the physical — will depend our interpretation of them in the intellectual and in the moral; from all which it follows, that our system of human economy will present, even as it has ever presented, a practical exhibition of that of the universe. There is more consistency in the human mind, as in the course of events, than is supposed. In both, the first link in the chain decides the last. Man hath ever made a cosmogony in keeping with his views in physics; a scheme of government in keeping with his cosmogony; a theory of ethics in keeping with his government, and a code of law and theology in keeping with his ethics. Every perception of the human mind modifies human practice. Science is but the theory of art.