Board Thread:The Panopticon/@comment-1451563-20180913002703/@comment-5918438-20181003044150

And beyond that, it's simply a matter of perspective. "The Thirteenth Doctor looked back on her past lives", because it's from her perspective specifically.

But, "Across their many lives, the Doctor remained devoted to the planet Earth", or "The Doctor's sonic screwdriver proved to be an invaluable tool throughout their travels and escapades", or "The Doctor usually had a companion by their side" -- all use they/them pronouns, because of the broader perspective.

Meanwhile, "The Fourth Doctor had spent much of his last incarnation working for UNIT on Earth".