He, She, or They?

Speakers of the English language--be they native or not--often feel a certain angst when writing about persons of indefinite grammatical gender. We mean one person, but is that hypothetical person male or female? In speaking, we often say "they" but in writing we've been taught either to write "he" or "he or she".
I have run across an interesting linguistic discussion of the numerous historical precedents for using "they" to refer to a single person of unspecified gender. Apparently, people were saying "they" and "their" to refer to nonspecific people for hundreds of years before grammarians decided that this was wrong and not like Latin. Numerous quite literate authors dared use this form in written language as well.
So, while it still sounds incorrect to me in written English (I don't mind it at all in spoken), we have plenty of excuse to write things like "Every child loves their mother."
As the web site referred to above notes, "Already in 1894, the famed grammarian and linguist Otto Jespersen (who was decidedly not a feminist himself) wrote in his book Progress in Language: With Special Reference to English (§24) that 'it is at times a great inconvenience to be obliged to specify the sex of the person spoken about. [...] if a personal pronoun of common gender was substituted for he in such a proposition as this: "It would be interesting if each of the leading poets would tell us what he considers his best work", ladies would be spared the disparaging implication that the leading poets were all men.' (so that it can hardly be claimed that a concern about such matters is only a recent outgrowth of 1970's feminism or so-called 'PC' ideology)."
Of course, Czech and many other Indo-European languages avoid this by having a more strictly gendered approach to language. This has its own pitfalls. A group of Czech women is clearly female, but a mixed group could be mistaken for male, linguistically.