In a manner that is clearly demonstrated or logically proved; with absolute certainty.
From 'apodeictic' or 'apodeictical' plus the adverbial suffix '-ly,' transforming the adjective into an adverb describing how something is done or stated.
This adverb is the kind of word philosophers use when they want to sound absolutely certain—it's not just 'true,' but true in the strongest possible way, proven by rigorous logic.
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