>Originally, most Indo-European languages had the three classes of feminine, masculine, and neuter.
Early Proto-Indoeuropean is theorized to have 2 genders - animate/inanimate, but by the late PIE period it evolved to the classic three.
Early Proto-Indoeuropean is theorized to have 2 genders - animate/inanimate, but by the late PIE period it evolved to the classic three.
Of course, this is largely theoretical like you said, and I'm sure you could dig up some dissenting papers if you wanted to.
For example, there are some adjectives in Latin and Ancient Greek, which only have two declensions instead of three: one common declension for masculine/feminine, and one for neuter.
For example: naturalis (masc), naturalis (fem), naturale (neut), as opposed to novus (masc), nova (fem), novum (neut).
Edit: Oh, I translated this as alive/not alive. Guess, this was originally down to soul. Not advocating to go down that path again…