1. If you remove the words "in [the] 18th century" from your paraphrase, then yes, more or less" (the scope is beauty in general, or at least since the 18th century, not merely in the 18th century). It may be debatable whether "definition" is the correct word in both places.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.