The Metaphysical Elements of Ethics by Immanuel Kant Chapter 5 Page 5

of the word (which even involves a contradiction), it must be observed that the feeling of the former belongs solely to the preceding head, namely, perfection. For he who is to feel himself happy in the mere consciousness of his uprightness already possesses that perfection which in the previous section was defined as that end which is also duty.

If happiness, then, is in question, which it is to be my duty to promote as my end, it must be the happiness of other men whose (permitted) end I hereby make also mine. It still remains left to themselves to decide what they shall reckon as belonging to their happiness; only that it is in my power to decline many things which they so reckon, but which I do not so regard, supposing that they have no right to demand it from me as their own. A plausible objection often advanced