In his 37-book Natural History, Pliny the Elder (d. ad 79) wondered why we wished people ‘Happy new year’ (primum anni diem laetis precationibus faustum ominamur), or said ‘Bless you’ (sternuentes salutamus) when someone sneezed. Was this mere superstition, or something else?

Pliny devoted a lot of time to denigrating all forms of superstition and magic, arguing that they were attempts to control the uncontrollable in human affairs, and citing Nero as an example of someone whose interest in magic was nothing but an ‘overwhelming desire to force the gods to do his will’, as if such a thing were ever...