supervenient behaviorism See PHILOSOPHY OF. MIN. suppositio (Latin, ‘supposition’), in the Middle Ages, reference. The theory of supposition, the central notion in the theory of proprietates terminorum, was developed in the twelfth century, and was refined and discussed into early modern times. It has two parts (their names are a modern convenience). (1) The theory of supposition proper. This typically divided suppositio into ‘personal’ reference to individuals (not necessarily to persons, despite the name), ‘simple’ reference to species or genera, and ‘material’ reference to spoken or written expressions. Thus ‘man’ in ‘Every man is an animal’ has personal supposition, in ‘Man is a species’ simple supposition, and in ‘Man is a monosyllable’ material supposition. The theory also included an account of how the range of a term’s reference is affected by tense and by modal factors. (2) The theory of ‘modes’ of personal supposition. This part of supposition theory divided personal supposition typically into ‘discrete’ (‘Socrates’ in ‘Socrates is a man’), ‘determinate’ (‘man’ in ‘Some man is a Greek’), ‘confused and distributive’ (‘man’ in ‘Every man is an animal’), and ‘merely confused’ (‘animal’ in ‘Every man is an animal’). The purpose of this second part of the theory is a matter of some dispute. By the late fourteenth century, it had in some authors become a theory of quantification. The term ‘suppositio’ was also used in the Middle Ages in the ordinary sense, to mean ‘assumption’, ‘hypothesis’. P.V.S.