There are a set of factors which can be viewed both as independent and interdependent in social development: technology, science and philosophy.
While philosophy and science took a beating for much of the medieval period, major technological developments proceeded independent of this -- the three field system, major improvements in metallurgy and the heavy plough.
Similarly, science and philosophy, while often linked can also proceed independently so that one can have a society which is becoming more scientifically sophisticated even as its capacity to discuss philosophical concepts is in decline (such as modern capitalism or Soviet communism).
Therefore, it's my inclinate to treat magic as a variable that is as dependent on these other things as you want it to be.
Thus, one can design a society in which the magic theory is to real magic as modern chemistry is to the physical sciences (ie. an actual, if incomplete, understanding) or one can design a society in which magic theory is to real magic as alchemy was to the physical sciences (ie. a mixture of sound observational data and apocrypha integrated into a system premised on false ideas). Or, one can design a society in which magic theory is to real magic as Platonism is to the physical sciences (ie. completely unrelated). It's really up to you.
While philosophy and science took a beating for much of the medieval period, major technological developments proceeded independent of this -- the three field system, major improvements in metallurgy and the heavy plough.
Similarly, science and philosophy, while often linked can also proceed independently so that one can have a society which is becoming more scientifically sophisticated even as its capacity to discuss philosophical concepts is in decline (such as modern capitalism or Soviet communism).
Therefore, it's my inclinate to treat magic as a variable that is as dependent on these other things as you want it to be.
Thus, one can design a society in which the magic theory is to real magic as modern chemistry is to the physical sciences (ie. an actual, if incomplete, understanding) or one can design a society in which magic theory is to real magic as alchemy was to the physical sciences (ie. a mixture of sound observational data and apocrypha integrated into a system premised on false ideas). Or, one can design a society in which magic theory is to real magic as Platonism is to the physical sciences (ie. completely unrelated). It's really up to you.