The Problem:
We have words for "he" and "she", but no word that makes no gender distinction. This leads us to say "he" when we mean "he or she." It also requires us to know what gender a person is when it is otherwise not necessary.
The Social Invention:
I propose we use a gender-neutral third-person pronoun, which means "he" or "she" without specifying gender. The word I suggest is "ta," which comes from Mandarin Chinese. Instead of "He went to the store" or "She went to the store", we would say, "Ta went to the store." Similarly, "I met him last week" or "I met her last week" would become "I met ta last week." We don't have to give up using the words "he" or "she" if we don't want to.
For those of you who think it's a radical idea, consider this: We don't have gendered words for "I/me" and "you" (but some languages do). Also, many languages have a word that means the same thing as "ta."