Once I dreamed I was a butterfly — fluttering about, completely a butterfly, aware only of my existence as a butterfly, with no awareness of Zhuangzi. Then I woke, and there I was, unambiguously Zhuangzi. But I do not know: was I then a man dreaming of being a butterfly, or am I now a butterfly dreaming of being a man?
This is not a riddle requiring a...

— Zhuangzi, Zhuangzi, ch. 2, 'Discussion on Making All Things Equal' (c. 300 BC); Burton Watson translation (Columbia University Press, 1968).
Ancient China