For duty is to be a practical, unconditional necessity of ac- tion; it must therefore hold for all
beings (to whom an im- perative can apply at all), and for this reason only be also a law for all human wills.
The-Critique-of-Practical-Reason-The-Metaphysical-Elements-of-Ethics-and-Fundamental-Principles-of-the-Metaphysic-of-Morals-by-Immanuel-Kant
