This is an excerpt from Dr. Deborah Tannen's advice on writing a discourse paper:
Avoid the generic masculine. Although some prescriptive grammarians proclaim that "he" means "he or she," linguists are descriptivists, not prescriptivists. According to Mühlhäusler and Harré (Pronouns and People), the generic masculine was a grammatical innovation that did not emerge as the natural development of language use but was imposed by grammarians in the 18th and 19th centuries, based on Latin grammar; before that, from at least about 1500, the correct sex-indefinite pronoun was "they," as it still is in spoken English. Furthermore, who is to say it is better to violate gender agreement rather than number? More important, research shows that readers and hearers think "masculine" when they read or hear "he," "him," "himself," etc. Try plural; try rewording your sentence; you may resort to "one," "s/he," "she or he," or "he or she."
And now you know.