Walter Segrave's 'Insolubles': a restrictivist response to Bradwardine

Walter de Segrave was at Merton College, Oxford from 1321 until at least 1338. Segrave's 'Insolubles' is his only known work, which appears to have been composed at Oxford in the late 1320s or early 1330s, consistent with the fact that it is clearly a response to Bradwardine's own 'Insolubles', composed when Bradwardine was regent master at Balliol College, that is, from 1321-23, before he moved to Merton in 1323. The dominant theory at the time Bradwardine was writing was restrictivism, the claim that a part cannot supposit for the whole of which it is part (and consequently, for its contradictory or anything convertible with it), at least in the presence of a privative term, in particular, privative alethic and epistemic terms such as 'false' and 'unknown'. Accordingly, Bradwardine spends two and a half chapters attacking restrictivist theories, in particular, that of Walter Burley. Segrave's treatise is an extensive and detailed response to Bradwardine. He defends restrictivism by presenting a well-thought out reason for the restriction of supposition required to avoid contradiction. Where Burley and Bradwardine both attributed the fallacy in insolubles to what Aristotle described as the fallacy of the conditional and the unconditional (secundum quid et simpliciter), Segrave attributed it to the fallacy of accident, turning on a variation in the supposition of the middle term and the extremes in what might otherwise appear to be a sound syllogism.