Immanuel Kant (1785)
Introduction to the Metaphysics of Morals

General Divisions of the Metaphysic of Morals

Source: Steve Palmquist’s web site;
Translated: by W. Hastie.

I. Division of the Metaphysic of Morals as a System
Duties Generally.

1. All duties are either duties of right, that is, juridical duties (officia juris), or duties of virtue, that is, ethical duties (officia virtutis s. ethica). Juridical duties are such as may be promulgated by external legislation; ethical duties are those for which such legislation is not possible. The reason why the latter cannot be properly made the subject of external legislation is because they relate to an end or final purpose, which is itself, at the same time, embraced in these duties, and which it is a duty for the individual to have as such. But no external legislation can cause any one to adopt a particular intention, or to propose to himself a certain purpose; for this depends upon an internal condition or act of the mind itself. However, external actions conducive to such a mental condition may be commanded, without its being implied that the individual will of necessity make them an end to himself. But why, then, it may be asked, is the science of morals, or moral philosophy, commonly entitled — especially by Cicero — the science of duty and not also the science of right, since duties and rights refer to each other? The reason is this. We know our own freedom — from which all moral laws and consequently all rights as well as all duties arise — only through the moral imperative, which is an immediate injunction of duty; whereas the conception of right as a ground of putting others under obligation has afterwards to be developed out of it.

2. In the doctrine of duty, man may and ought to be represented in accordance with the nature of his faculty of freedom, which is entirely supra-sensible. He is, therefore, to be represented purely according to his humanity as a personality independent of physical determinations (homo noumenon), in distinction from the same person as a man modified with these determinations (homo phenomenon). Hence the conceptions of right and end when referred to duty, in view of this twofold quality, give the following division:

Division of the Metaphysic of Morals according to the Objective Relation of the Law of Duty.

I. The Right of Humanity. 
I. Juridicalto Oneselfin our own person (juridicialPerfect
Dutiesor Othersduties towards oneself)Duty
II. The Right of Mankind. 
in others (juridical duties 
towards others.) 
III. The End of Humanity. 
II. Ethicalto Oneselfin our person (ethical dutiesImperfect
Dutiesor Otherstowards oneself) Duty
IV. The End of Mankind. 
in others (ethical towards others.) 

II. Division of the Metaphysic of Morals according to Relations of Obligation.

As the subjects between whom a relation of right and duty is apprehended — whether it actually exists or not — admit of being conceived in various juridical relations to each other, another division may be proposed from this point of view, as follows:

Division possible according to the Subjective Relation of those who Bind under Obligations, and those who are Bound under Obligations.

1. The juridical relation of man to beings who have neither right nor duty:

Vacat. There is no such relation, for such beings are irrational, and they neither put us under obligation, nor can we be put under obligation by them.

2. The juridical relation of man to beings who have both rights and duties:

Adest. There is such a relation, for it is the relation of men to men.

3. The juridical relation of man to beings who have only duties and no rights:

Vacat. There is no such relation, for such beings would be men without juridical personality, as slaves or bondsmen.

4 The juridical relation of man to a being who has only rights and no duties (God):

Vacat. There is no such relation in mere philosophy, because such a being is not an object of possible experience.

A real relation between right and duty is therefore found, in this scheme, only in No. 2. The reason why such is not likewise found in No. 4 is because it would constitute a transcendent duty, that is, one to which no corresponding subject can be given that is external and capable of imposing obligation. Consequently the relation from the theoretical point of view is here merely ideal; that is, it is a relation to an object of thought which we form for ourselves. But the conception of this object is not entirely empty. On the contrary, it is a fruitful conception in relation to ourselves and the maxims of our inner morality, and therefore in relation to practice generally. And it is in this bearing that all the duty involved and practicable for us in such a merely ideal relation lies.

III. Division of the Metaphysic of Morals as a System of Duties Generally.

According to the constituent principles and the method of the system.

I. PrinciplesI. Duties of RightI. Private Right.
II. Public Right
 II. Duties of Virtue, etc.
And so on, including all that refers not only to the materials, but also to the architectonic form of a scientific system of morals, when the metaphysical investigation of the elements has completely traced out the universal principles constituting the whole.
II. MethodI. Didactics
II. Ascetics