…really is indistinguishable from magic. As Mike Flynn says,

In the Middle Ages, “magic” meant employing some nature of a material body to achieve an effect without knowing the nature that achieved it. Thus, chewing willow bark would relieve a headache somehow. It was the “somehow” that made it magic. Had they known the nature of willow bark and how it influenced bodily humours, it would not have been magic. The causes would have been “manifest” (apparent) rather than “occult” (hidden). This was quite different from sorcery, although there is obvious scope for both quacks and superstition when the natures are occult. [Superstition is when the effect is falsely ascribed to the nature of the matter, such as might happen from a spurious correlation or post hoc, propter hoc reasoning.] Since then, of course, the terms “magic” and “occult” have taken on the odor of “unnatural” or “supernatural” rather than merely “unknown nature.”

The Medievals were familiar with Clarke’s Third Law. Who knew?

(H/T Mark Shea)