Immanuel Kant (1724–1804) argued that the supreme principle of morality is a standard of rationality that he dubbed the “Categorical Imperative” (CI). Kant characterized the CI as an objective, rationally necessary and unconditional principle that we must always follow despite any natural desires or inclinations we may have to the contrary.

Justice as fairness is Rawls's theory of justice for a liberal society. As a member of the family of liberal political conceptions of justice it provides a framework for the legitimate use of political power. Yet legitimacy is only the minimal standard of moral acceptability; a political order can be legitimate without being just. Justice sets the maximal standard: the arrangement of social institutions that is morally best.

As Elie Halévy (1904) notes, there are three principal characteristics of which constitute the basis of Bentham's moral and political philosophy: (i) the greatest happiness principle, (ii) universal egoism and (iii) the artificial identification of one's interests with those of others. Though these characteristics are present throughout his work, they are particularly evident in the Introduction to the Principles of Morals and Legislation, where Bentham is concerned with articulating rational principles that would provide a basis and guide for legal, social and moral reform.

Instead of theorizing that life is aimed at any final good, Thomas Hobbes claims that we aim at felicity, which he defines as “continual success in obtaining those things which a man from time to time desireth, that is to say, continual prospering” (Ch6, p597).

Every true deed is a loving deed. All true deeds arise from contact with a beloved thing and flow into the universe. Any true deed brings, out of lived unity, unity into the world. Unity is not a property of the world but its task. To form unity out of the world is our never‐ending work.