Today, many scholars view Ovid as a "remythologizer," who took existing scientific and historical theories and sort of added the gods back into them. If this is true, however, it still means Ovid had to have extensive knowledge of the scientific theories of his day; otherwise, how could he deliberately modify them? The intersection of scientific and mythological theories can be seen at many points in The Metamorphoses, most notably in the passage about the creation of the universe from Book 1. Here, Ovid compromises by depicting an unnamed "god" who helps out in the creation process, while at the same time giving an account of the four elements (Fire, Air, Water, and Earth) in keeping with the scientific theories of his day. Especially striking is the lengthy speech Ovid gives to the philosopher Pythagoras in Book 15. This speech provides a scientific or philosophical basis for the entire theme of Transformation; it, more than any other moment in the work, shows Ovid's deep familiarity with the science of his era.
Ovid agrees with Pythagoras and thinks that his own myths are fictional.
Ovid's myths cannot be interpreted as metaphors for physical processes. Thus, they are fundamentally unscientific.