Since the Old English use of man to mean ‘a human being’ has been largely co-opted at this stage in the history of English to mean ‘a male human being’, many people have rightly sought new, gender-neutral/inclusive nouns to refer to individual human persons.
The most common solution is person/persons (or people). However, this does not work in all cases, since in some domains, human beings are not the only persons potentially under discussion. The realms that come to mind in this regard are theology, mythology, and science fiction and fantasy. In the last dual category of genre fiction, Star Trek calls us earthlings humans (pronounced by Quark the Ferengi as ‘humahns’). Obviously, many non-humans in Star Trek are persons — Odo and Hu, just to mention those who’ve already made an appearance on this blog. But all humanoid species and many non-humanoid species in Trek are persons. Even Q, the space fairy.
I am actually less certain about fantasy, since I do not read a lot of new fantasy. In Tolkien, the human species is populated by Men with a capital ‘M’, reflecting both the archaic nature of the language and its cadence as used by Tolkien as well as Tolkien’s own era.
In mythology, one has a variety of non-human persons. The concern here arises for translators and philologists who want to discuss literature in the Classical tradition. How do you render anthropos and homo? It cannot be person, since by current English usage, gods, demi-gods, centaurs, et al., are also persons.
Similarly in theology. In Christian theology, God is a Trinity of Persons, so it is actually imprecise to use person where a few decades ago one would have used man. Mankind also runs into similar problems, often solved by humankind, a word I dislike; much better to say humanity, I think. One place where this is a difficulty is Genesis 1, where God speaks of making, in older translations, ‘man in our image’. Andrew Louth circumvented this danger in Introducing Eastern Orthoodox Theology by consistently rendering (from Greek, not Hebrew) anthropos as human kind until he had to bring the discussion to the singular.
Many current English translations of the Bible and ancient Christian literature seem to think person is a perfect synonym for anthropos. Or, in the case of new translations of the Nicene Creed, cut men out altogether, ‘who for us and for our salvation’. Loses some of the theological potency; us what?
One of the books that is consistent in using one solution to the problem is Greta Austin, Shaping Church Law Around the Year 1000: The Decretum of Burchard of Worms. She consistently always refers to human beings using the substantive humans. This works. It is not as common as it should be, although I see it every once in a while. The philological objection is, of course, that human is an adjective, not a noun. But adjectives are frequently nounified when necessary, and this maintains the linguistic precision of the Latin text under discussion as well as the theological context of Burchard.
Perhaps not a breakthrough or deep or illuminating, but it is important for us to keep in mind not only why we may wish to shift our lexicon away from something, but also to consider where we are turning. Precision and accuracy are important, and person is often too imprecise for accuracy in language.