My five-and-a-half-year-old used this word a few days ago, and I gently corrected him. We say “himself,” I said, not “hisself.” I’m a descriptivist when it comes to determining what is “correct”; but I want my child to learn not just any correct way of speaking, but the way that is going to best help him get ahead in life, which sometimes mean the mode of speaking that is most satisfying to self-described “purists.” Plus even a descriptivist treats deviations from standard usage as errors, at least in contexts where standard usage is expected (as opposed to, for instance, when one is consciously trying to speak a particular dialect). A Google search reveals that “himself” is nearly 100 times more common than “hisself,” so I’m happy to say that “himself” is the standard term and “hisself” is nonstandard.
But of course I also wanted my boy to get a sense of the patterns in the language, so I pointed out the analogies — “herself,” “themselves,” “myself.” Wait a minute! It’s “myself,” not “meself,” and “ourselves,” not “usselves”; the first-person reflexive uses the possessive (“my” and “our”) followed by “self” or “selves.” But the others use the objective (“him,” “her,” “them”) and not the possessive.
And what is it that tells us that “myself” and “himself” are right, while “meself” and “hisself” are wrong? Not any supposed inner logic of the language, it seems to me, but simply usage: “Myself” and “himself” are standard among educated English speakers, at least outside narrow regional dialects, and “meself” and “hisself” are not. What is right to say in English is what educated English speakers say.
So when I hear prescriptivists argue using what I think of as “logical prescriptivism” — this spelling or usage is right and that is wrong because of some inner logic of the word, or because of an analogy to other words — I remember examples like this. Or I remember how “aren’t I right?” is right and “amn’t I right?” is at least extremely unusual; or how “it’s” as a possessive of “it” remains nonstandard in educated edited prose, even though for non-pronouns this is exactly how possessives are formed.
To be sure, logic and analogy have their uses in language. They can sometimes be good mnemonics. They can sometimes be good guides to what will come across as confusing, or will arouse the wrong associations. They can be good guides when creating new terms, and trying to make them clear and normal-looking. But when usage conflicts with the supposed logic of the language, usage prevails. If it didn’t, we’d be saying “hisself” and “myself,” or “himself” and “meself.”