According to Fundamental Principles of the Metaphysic of Morals, by Immanuel Kant, 1724-1804.
What do we think of Kant’ “supreme principle of morality?” Are there problems with his system? Does the Categorical Imperative give us a workable moral system?
https://ebooks.adelaide.edu.au/k/kant/immanuel/k16prm/chapter2.html