I had always thought there was a dialect of English where _he_ could be used as a gender-neutral pronoun. That is, I always thought there was a dialect of English where one could say (1) without presupposing that the person we hire next will be male.
(1) The person we hire next will be able to teach whatever courses he wants.
Now I always (or at least as long as I can remember) thought it was a bad idea to speak such a dialect, because there was the obvious possibility for confusion between the gender-neutral pronoun and the gender-biased pronoun. And since the effects of such confusion could easily be to reinforce stereotypes and assumptions that shouldn’t be reinforced, I thought it was _politically_ bad idea as well as being an inefficient means of communication. But as I said, I thought there was such a dialect.
Geoff Pullum “has convinced me otherwise”:http://itre.cis.upenn.edu/~myl/languagelog/archives/001362.html. There is no such dialect of English. If there was, there would be a dialct of English where the following sentences would be acceptable.
* *Either the husband or the wife has perjured himself.
* *Was it your father or your mother who broke his leg on a ski trip?
And clearly neither of these is acceptable in _any_ dialect of English. So I now think that using ‘he’ as a purportedly gender-neutral pronoun doesn’t involve speaking a dialect I’d rather wasn’t used, it is just a mistake. As Geoff points out, English has a perfectly adequate gender-neutral pronoun – _they_ – and it should be used instead of _he_ in these contexts.