Immanuel Kant 'On Servility' MM, III section 11.

"...Humanity in his person is the object of the respect to which he can demand from every other human being, but which he must also not forfeit. Hence he can and should value himself by a low as well as by a high standard, depending on whether he views himself as a sensible being in terms of his animal nature) or as an intelligible being (in terms of his moral predisposition) {and by this Kant means a predisposition towards the Good.--Feng}. Since he must regard himself not only as a person generally but also as a human being, that is, as a person who has duties his own reason lays upon him, his insignificance as a human animal may not infringe upon his consciousness of his dignity as a rational human being, and he should not disavow the moral self-esteem of such a being, that is, he should pursue his end, which is in itself a duty, not abjectly, not in a servilespirit as if he were seeking a favor, not disavowing his dignity, but always with consciousness of his sublime moral predisposition (which is already contained in the concept of virtue). And this self-esteemis a duty of man to himself." Immanuel Kant The Metaphysics of Morals 6:435-6.