It's not just that they didn't have a scientific method, it's that empiricism was a swear word. You were supposed to understand the universe through intellectual extrapolation of the Bible or of greek philosophy - not by dumbly testing out things in the real world until you found a consistent pattern. The scientific method is kind of the first instance of the Bitter Lesson.
Ironically, occultists had no such snobbery, that's why people like Paracelsus were able to be so influential even though their whole framework was basically fantasy. Just the fact that they would perform structured experiments and consign the results and use those results to establish theories put them head and shoulder above the rest.