Conceptual Shift
I wrote here, "It's important that it's X and X'."
There is no clear switching epoch, and both concepts are referred to by the same term because they move smoothly
This is illustrated even more clearly
https://gyazo.com/ba9045303f6e5786b578be1c5f68fe01
At some point the word X meant A or B, not C.
At another point in time, the word X meant B or C and no longer meant A.
---
This page is auto-translated from /nishio/概念のシフト using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.