In lang=en terms the difference between reify and substantiate

is that reify is to regard something abstract as if it were a concrete material thing while substantiate is to give material form or substance to something; to embody; to record in documents.

As verbs the difference between reify and substantiate

is that reify is to regard something abstract as if it were a concrete material thing while substantiate is to verify something by supplying evidence; to authenticate or corroborate.