Kant’s three significant formulations of the categorical imperative are:
- Act only according to that maxim by which you can also will that it would become a universal law.
- Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end.
- Every rational being must so act as if he were through his maxim always a legislating member in a universal kingdom of ends.
He concludes that there is only one thing that is truly good:
Nothing in the world – indeed nothing even beyond the world – can possibly be conceived which could be called good without qualification except a good will.
My definition of morality – striving to eliminate suffering – is Kant’s maxim. It’s also the most significant manifestation of good will that was the most important for him.