A. “To do something from duty means: to obey reason” (Lectures on Pedagogy 9:483).
B. “Love, like water, always flows downward more easily than upward” (Metaphysics of Morals Vigilantius 27:670).
C. “Many people take pleasure in doing good actions but consequently do not want to stand under obligation to others. If one only comes to them submissively, they will do everything: they do not want to subject themselves to the rights of people, but to view them simply as objects of magnanimity. It is not all one under what title I get something. What properly belongs to me must not be accorded to me merely as something I beg for” (Notes Ak 19:145).
D. “[In] the formal principle of duty, in the categorical imperative ‘So act that the maxim of your action could become a universal law,’…maxims are regarded as subjective principles which merely qualify for a giving of universal law, and the requirement that they so qualify is only a negative principle (not to come into conflict with law as such). – How can there be, beyond this principle, a law for the maxims of actions?...
For maxims of actions can be arbitrary [willkürlich], and are subject only to the limiting condition of being fit for a giving of universal law, which is the formal principle of actions. A law, however, takes away the arbitrariness of actions” (Metaphysics of Morals 6: 389).
E. “Only the concept of an end that is also a duty, a concept that belongs exclusively to ethics, establishes a law for maxims of actions by subordinating the subjective end that everyone has to the objective end…
The supreme principle of the doctrine of virtue is: act in accordance with a maxim of ends that it can be a universal law for everyone to have. – In accordance with a this principle a human being is an end for himself as well as for others, and it is not enough that he is not authorized to use either himself or others merely as means;… it is in itself his duty to make the human being as such his end” (Metaphysics of Morals 6:389, 395).
F. “The capacity to set oneself an end – any end whatsoever – is what characterizes humanity (as distinguished from animality). Hence there is also bound up with the end of humanity in our own person the rational will, and so the duty, to make ourselves worthy of humanity by culture in general, by procuring or promoting the capacity to realize all sorts of possible ends” (Metaphysics of Morals 6:392).
G. “The reason it is a duty to be beneficent is this: since our self-love cannot be separated from our need to be loved (helped in case of need) by others as well, we therefore make ourselves an end for others; and the only way this maxim can be made binding is through its qualification as a universal law, hence through our will to make others our ends as well” (MS: 6:393).
H. “The wider the duty, therefore, the more imperfect is a human being’s obligation to action; as he nevertheless brings closer to narrow duty (duties of right) the maxim of complying with wide duty (in his disposition), so much the more perfect is his virtuous action” (Metaphysics of Morals 6:390).
I. “Self-regarding duties do not depend on the relation of actions to the ends of happiness…. All such duties are founded on a certain love of honor consisting in the fact that a human being values himself, and in his own eyes is not unworthy that his actions should be in keeping with humanity” (Moral Philosophy Collins 27:343, 347).
J. “The human being has a general duty of so disposing himself that he may be capable of observing all moral duties…This, then, is the primary duty to oneself…[This duty] takes first place and is the most important of all” (Moral Philosophy Collins 27: 348, 341).