Next time someone complains about singular "they" I'll point them to this 17th century rant against singular "you"
Source: The History of Thomas Elwood, written by Himself, London, 1885, pp. 32-34, https://www.gutenberg.org/ebooks/6925
Discovered from cite in "The Varieties of Religious Experience," by William James, 1902.
@arkiuat @mwl Fox (et al.) wrote an entire book on the subject! (Text available online at the link. The title is far too long to be contained in a toot.)