Shepherd Mary (d.1847), Scottish philosopher whose main philosophical works are An Essay on the Relation of Cause and Effect (1824) and Essays on the Perception of an External Universe (1827). The first addresses what she takes to be the skeptical consequences of Hume’s account of causation, but a second target is the use William Lawrence (1783–1867) made of Hume’s associative account of causation to argue that mental functions are reducible to physiological ones. The second work focuses on Hume’s alleged skepticism with regard to the existence of the external world, but she is also concerned to distinguish her position from Berkeley’s. Shepherd was drawn into a public controversy with John Fearn, who published some remarks she had sent him on a book of his, together with his extensive reply. Shepherd replied in an article in Fraser’s magazine (1832), ‘Lady Mary Shepherd’s Metaphysics,’ which deftly refuted Fearn’s rather condescending attack. See also BERKELEY, HUM. M.At. Sherwood, William, also called William Shyreswood (1200/10–1266/71), English logician who taught logic at Oxford and at Paris between 1235 and 1250. He was the earliest of the three great ‘summulist’ writers, the other two (whom he influenced strongly) being Peter of Spain and Lambert of Auxerre (fl. 1250). His main works are Introductiones in Logicam, Syncategoremata, De insolubilibus, and Obligationes (some serious doubts have recently arisen about the authorship of the latter work). Since M. Grabmann published Sherwood’s Introductiones in 1937, historians of logic have paid considerable attention to this seminal medieval logician. While the first four chapters of Introductiones offer the basic ideas of Aristotle’s Organon, and the last chapter neatly lays out the Sophistical Refutations, the fifth tract expounds the famous doctrine of the properties of terms: signification, supposition, conjunction, and appellation – hence the label ‘terminist’ for this sort of logic. These logico-semantic discussions, together with the discussions of syncategorematic words, constitute the logica moderna, as opposed to the more strictly Aristotelian contents of the earlier logica vetus and logica nova.
The doctrine of properties of terms and the analysis of syncategorematic terms, especially those of ‘all’, ‘no’ and ‘nothing’, ‘only’, ‘not’, ‘begins’ and ‘ceases’, ‘necessarily’, ‘if’, ‘and’, and ‘or’, may be said to constitute Sherwood’s philosophy of logic. He not only distinguishes categorematic (descriptive) and syncategorematic (logical) words but also shows how some terms are used categorematically in some contexts and syncategorematically in others. He recognizes the importance of the order of words and of the scope of logical functors; he also anticipates the variety of composite and divided senses of propositions. Obligationes, if indeed his, attempts to state conditions under which a formal disputation may take place. De Insolubilibus deals with paradoxes of self-reference and with ways of solving them. Understanding Sherwood’s logic is important for understanding the later medieval developments of logica moderna down to Ockham. I.Bo.