This chapter examines Immanuel Kant’s ethical theory in all its aspects and it up to its final theological position. Kant's ethical theory forms an integral part of his philosophy, for it is in the - requirements of moral reason that he finds the necessity for conceiving the reality of the some Ideas of pure reason. The moral law, demanding as it does the conception of the summum bonum as the ultimate goal of humanity, finally leads to religion. If the idea of complete good is to be attained, it becomes not only possible but necessary to postulate the existence of God. In Christianity the worth of a character perfectly in accord with the moral law is infinite, and the only hindrance to all possible happiness to humanity is lack of morality. The moral law and the conception of the summum bonum which it commands to strive towards.