in AD 700 one would absolutely have been able to explain an outbreak with a miasma-based model, and the explanation absolutely would have become consensus among the best and brightest. you can't apply what we know now to what was known at a given point in the past

> we can explain why things fall down

that's pretty new too! and it's not semantically correct, but was considered so for quite a while. this is a pretty good analogy for why i'm skeptical of dark matter