I recently saw a rule that confuses me regarding qualitative adjectives. It says absolute qualities should not be modified by additional adjectives if they are comparative or superlative.
One example was "delicieux", it is an absolute quality and one should not say "c'est tres delicieux". To me, this makes no sense. If true, many people break the rule. Plus, I don't consider "tres" a comparative or superlative. Some of the other examples given were "éternel, parfait & admirable". I did a lot of searching and can find no other references, but I may be missing a magic keyword. I would ignore it except that the source is usually good and it was in the context of "very common French errors"
The rule does seem to make sense with some adjectives, from an English perspective. One would not say something is "very eternal", it's either eternal or it's not. I don't see delicious the same way.
Am I misunderstanding this? Can someone clarify?