I insist on using "he" or 'his" as the third person indefinite pronoun. While it may be politically correct to use "they" or "their"--as in "from each according to their ability, to each according to their needs"--it strikes me as ungrammatical.
I used to work with a tech/document writer (female) that insisted that he/his etc, were grammatically correct uses for the third person, even in the touchy feely political correct world we find ourselves in. She even publicly chastised supervisors for trying to be PC about their grammar.