“Morality is thus the relation of actions to the autonomy of the will, that is, to a possible giving of universal law through its maxims.”

Ten Sermons of Religion (1853), III : Of Justice and the Conscience https://en.wikisource.org/wiki/Ten_Sermons_of_Religion/Of_Justice_and_the_Conscience
Context: Justice is the constitution or fundamental law of the moral universe, the law of right, a rule of conduct for man in all his moral relations. Accordingly all human affairs must be subject to that as the law paramount; what is right agrees therewith and stands, what is wrong conflicts and falls. Private cohesions of self-love, of friendship, or of patriotism, must all be subordinate to this universal gravitation towards the eternal right.

Der kategorische Imperativ, der überhaupt nur aussagt, was Verbindlichkeit sei, ist: handle nach einer Maxime, welche zugleich als ein allgemeines Gesetz gelten kann.
Source: Metaphysics of Morals (1797), Ch. 11

Six Principles of Political Realism, § 4.
Politics Among Nations (1948)
Context: Realism maintains that universal moral principles cannot be applied to the actions of states in their abstract universal formulation, but that they must be filtered through the concrete circumstances of time and place. The individual may say for himself: "Fiat justitia, pereat mundus (Let justice be done, even if the world perish)," but the state has no right to say so in the name of those who are in its care. Both individual and state must judge political action by universal moral principles, such as that of liberty. Yet while the individual has a moral right to sacrifice himself in defense of such a moral principle, the state has no right to let its moral disapprobation of the infringement of liberty get in the way of successful political action, itself inspired by the moral principle of national survival.

Source: supanet.com/find/famous-quotes-by/axel-munthe/a-man-can-stand-a-lot-as-fqb50991/

1910's, Natural Reality and Abstract Reality', 1919

Groundwork of the Metaphysics of Morals (1785)
Context: I do not, therefore, need any penetrating acuteness to see what I have to do in order that my volition be morally good. Inexperienced in the course of the world, incapable of being prepared for whatever might come to pass in it, I ask myself only: can you also will that your maxim become a universal law?

Source: "Evolutionary Socialism" (1899) https://www.marxists.org/reference/archive/bernstein/works/1899/evsoc/index.htm, Chapter III, The Tasks and Possibilities of Social Democracy

Ich soll niemals anders verfahren als so, dass ich auch wollen könne, meine Maxime solle ein allgemeines Gesetz werden.
Kant's supreme moral principle or "categorical imperative"; Variant translations:
Act only on that maxim which you can at the same time will that it should become a universal law.
Act as if the maxim of thy action were to become by thy will a universal law of nature.
So act that your principle of action might safely be made a law for the whole world.
May you live your life as if the maxim of your actions were to become universal law.
Live your life as though your every act were to become a universal law.
Do not feel forced to act, as you're only willing to act according to your own universal laws. And that's good. For only willfull acts are universal. And that's your maxim.
Groundwork of the Metaphysics of Morals (1785)

Lectures on the History of History Vol 1 p. 40-41 John Sibree translation (1857), 1914
Lectures on the Philosophy of History (1832), Volume 1
Context: Subjective volition Passion is that which sets men in activity, that which effects" practical" realization. The Idea is the inner spring of action; the State is the actually existing, realized moral life. For it is the Unity of the universal, essential Will, with that of the individual; and this is “Morality." The Individual living in this unity has a moral "life; possesses a value that consists in this substantiality alone. Sophocles in his Antigone, says, "The divine commands are not of yesterday, nor of to-day; no, they have an infinite existence, and no one could say whence they came." The laws of morality are not accidental, but are the essentially Rational. It is the very object of the State that what is essential in the practical activity of men, and in their dispositions, should be duly recognized; that it should have a manifest existence, and maintain its position. It is the absolute interest of Reason that this moral Whole should exist; and herein lies the justification and merit of heroes who have founded states, however rude these may have been. In the history of the World, only those peoples can come under our notice which form a state. For it must be understood that this latter is the realization of Freedom, i. e. of the absolute final aim, and that it exists for its own sake. It must further be understood that all the worth which the human being possesses all spiritual reality, he possesses only through the State. For his spiritual reality consists in this, that his own essence Reason is objectively present to him, that it possesses objective immediate existence for him. Thus only is he fully conscious; thus only is he a partaker of morality of a just and moral social and political life. For Truth is the Unity of the universal and subjective Will; and the Universal is to be found in the State, in its laws, its universal and rational arrangements. The State is the Divine Idea as it exists on Earth. We have in it, therefore, the object of History in a more definite shape than before; that in which Freedom obtains objectivity, and lives in the enjoyment of this objectivity. For Law is the objectivity of Spirit; volition in its true form. Only that will which obeys law, is free; for it obeys itself; it is independent and so free. When the State or our country constitutes a community of existence; when the subjective will of man submits to laws, the contradiction between Liberty and Necessity vanishes. The Rational has necessary existence, as being the reality and substance of things, and we are free in recognizing it as law, and following it as the substance of our own being. The objective and the subjective will are then reconciled, and present one identical homogeneous whole.