Mugnai, Massimo Leibniz’s theory of relations. (English) Zbl 0755.01018 Studia Leibnitiana. Supplementa. 28. Stuttgart: Franz Steiner. 291 p. (1992). Since Russell’s Critical exposition (1900), it has been clear that the theory of relations is a central issue in Leibniz’s philosophy, underlying his views on many other questions. Mugnai’s full-length study elucidates many of the obscure and sometimes apparently inconsistent things Leibniz says about relations in different works. The author includes as appendices Leibniz’s “Circa geometrica generalia” and a letter from Johann Vagetius with Leibniz’s comments (both here published for the first time), and also Leibniz’s “De partibus orationes” and his reflections and marginal notes on the Philosophia vera Theologiae et medicinae ministra by “Aloys Temmik” (perhaps the Jesuit Gaspar Kuemmet), both previously published. There is also a photographic reprint of the first part of the Temmik’s book, showing the marginal notes. The author places Leibniz in the context of his time, drawing on the treatment of relations in late scholastic philosophy from Duns Scotus and Ockham to Suarez and Toletus, which previous commentators on Leibniz have largely ignored. He neglects, however, the work on scholastic philosophy by modern logicians, notably D. P. Henry’s analysis of Scotus’s formal distinction. He surprisingly describes Ockham as a conceptualist. Leibniz was close to, but had not quite attained, the modern concept of a function (p. 91), and Leibniz had more awareness of the limits intensional contexts impose on substitutivity than some modern logicians credit him with (p. 109). Reviewer: J.Mackenzie (Sydney) Cited in 1 ReviewCited in 7 Documents MSC: 01A45 History of mathematics in the 17th century 00A30 Philosophy of mathematics 03-03 History of mathematical logic and foundations Keywords:relations; conceptualism; Ockham Biographic References: Leibniz, Gottfried Wilhelm PDFBibTeX XMLCite \textit{M. Mugnai}, Leibniz's theory of relations. Stuttgart: Franz Steiner (1992; Zbl 0755.01018)