Naturae vero rerum vis atque majestas in omnibus momentis fide caret, si quis modo partes ejus ac non totam coplectatur animo.1
Pliny, Natural History, VII.1.7
In the De natura deorum, Cicero recalls that followers of Pythagoras often justified justified their acceptance of a statement by appealing to the authority of their teacher. For them, inasmuch as Pythagoras “himself said it,” his words should be accepted unreservedly and there was no reason to argue further (Cicero, De natura deorum, 1.10).2 Since antiquity, “ipse dixit” has been considered the most straightforward summary of the argument from authority. It also seems to condense all of the negative characteristics of an attitude that we nowadays regard as the contrary to modern scientific rationality. It advocates dogmatism by pointing to complete reliance on the master’s views and denies the very possibility of innovation and change. All too...