Accidents which are altogether accidental are neglected by every art, by reason of their uncertainty and infinity.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic uncertainty infinity
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17897/pg17897-images.html

Context

“Accordingly, since the goodness of acts consists in their utility to the end, nothing hinders their being called good or bad according to their proportion to extrinsic things that are adjacent to them. Reply Obj. 2: Accidents which are altogether accidental are neglected by every art, by reason of their uncertainty and infinity. But such like accidents are not what we call circumstances; because circumstances although, as stated above (A. 1) , they are extrinsic to the act, nevertheless are in a kind of contact with it, by being related to it.” source