Linguist Geoffrey Pullum on the inadequacy of traditional definitions of a noun:
It is useless to look for a common ontological nature in airspeeds, apples, and absences, or organizations, orchids, and orgasms. To give a definition that permits decisions as to whether a given English word is a noun or not, you have to consider morphological and syntactic facts.I have on several occasions taken issue with what I see as Pullum’s distortions and exaggerations regarding The Elements of Style. Here though I think that Pullum is right. He and I agree about something after all.
[This post is for my son Ben, who has grammar and its problems on his mind.]