Nature is a proper noun? Okay, I'll grant you Nature, Science, Communism, and Christendom. But mankind, too? Really? Change, too? ("Change (abstract noun)

Nature is a proper noun? Okay, I'll grant you Nature, Science, Communism, and Christendom. But mankind, too? Really? Change, too? ("Change (abstract noun) is hard." vs "The change (menopause) is hard.") I chose the "One giant leap for mankind" example not because I didn't know that "one" is a determiner but because "one" and "a[n]" usually can't substitute for each other (with the usual complicated rules). Danish doesn't have this distinction at all, using the same two words for the cardinal number and the indeterminate article. I guess my point really was that determiners are hard -- and calling them adjectives doesn't help.