Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end.
Aus so krummen Holze, als woraus der Mensch gemacht ist, kann nichts ganz Gerades gezimmert werden. Out of the crooked timber of humanity, no straight thing can ever be made.
The philanthropists inquire whether Transcendentalism does not mean sloth: they had as lief hear that their friend is dead, as that he is a Transcendentalist; for then is he paralyzed, and can never do anything for humanity.
It is only great pain--that slow, sustained pain that takes its time, in which we are, as it were, burned with smoldering green firewood--that forces us philosophers to sink to our ultimate profundity and to do away with all the trust, everything good-natured, veil-imposing, mild and middling, on which we may have previously based our humanity. I doubt that such a pain makes us 'better'--but I know that it makes us deeper.
All of us living in today's world are facing an enormous crisis - arguably the greatest that humanity has ever faced - in the form of man-made global warming; one can't be neutral at such a moment. It's like claiming to be neutral if you're living in Germany in 1933.
There are some who esteem that it is a naivety to believe that a moral regeneration may be possible ("soit possible", Fr.); now, if this was not the case, it would not be worth the trouble that humanity continue to vegetate without aim.