> There are, again, a couple errors here: it should be “explicación phisica” [physical explanation] not “poetic explanation” in the first line, for instance.
The image seems to say "phicica" (with a "c"), but that's not Spanish. "ph" is not even a thing in Spanish. "Physical" is "física", at least today, IDK about the 1700's. So, if you try to make sense of it in such a way that you assume a nonsense word is you misreading rather than the writer "miswriting", I can see why it assumes it might say "poética", even though that makes less sense semantically.