What is "contrastivism"

n. (context philosophy English) An epistemological theory suggesting that knowledge attributions have a ternary structure of the form "''S'' knows that ''p'' rather than ''q''", in contrast to the traditional view whereby knowledge attributions have a binary structure of the form "''S'' knows that ''p''".

Contrastivism, or the contrast theory of meaning is an epistemological theory proposed by Jonathan Schaffer that suggests that knowledge attributions have a ternary structure of the form 'S knows that p rather than q'. This is in contrast to the traditional view whereby knowledge attributions have a binary structure of the form 'S knows that p'. Contrastivism was suggested as an alternative to contextualism. Both are semantic theories that try to explain skepticism using semantic methods.

Ernest Gellner in Words and Things, p. 40: "terms derive their meaning from the fact that there are or could be things which fall under them and that there are others which do not." (Emphasis in original.)