Richard Swineshead (a.k.a. Suisset, Suiseth, etc.) (fl. c. 1340 – 1354) was an English mathematician, logician, and natural philosopher. He was perhaps the greatest of the Oxford Calculators of Merton College, where he was a fellow certainly by 1344 and possibly by 1340. His magnum opus was a series of treatises known as the Liber calculationum ("Book of Calculations"), written c. 1350, which earned him the nickname of The Calculator.
Robert Burton (d. 1640) wrote in The Anatomy of Melancholy that "Scaliger and Cardan admire Suisset the calculator, qui pene modum excessit humani ingenii [whose talents were almost superhuman]".Gottfried Leibniz wrote in a letter of 1714: "Il y a eu autrefois un Suisse, qui avoit mathématisé dans la Scholastique: ses Ouvrages sont peu connus; mais ce que j'en ai vu m'a paru profond et considérable." ("There was once a Suisse, who did mathematics belonging to scholasticism; his works are little known, but what I have seen of them seemed to me profound and relevant.") Leibniz even had a copy of one of Swineshead's treatises made from an edition in the Bibliothèque du Roi in Paris.
Girolamo Cardano included Swineshead (as John Suisset surnamed the Calculator) on his famous list of 12 Greatest Minds. 
^Jackson, Holbrook (ed.) (1932), The Anatomy of Melancholy, i.77 (in "Democritus Junior to the Reader").
^Letter to M. M. Remond de Montmorency, quoted in Lardet, Pierre (2003) "Les ambitions de Jules–César Scaliger latiniste et philosophe (1484–1558) et sa rèception posthume dans l'aire germanique de Gesner et Schegk à Leibniz et à Kant", in Kessler & Kuhn (edd.), Germania latina – Latinitas teutonica, pp. 157–194.
As late as the end of the seventeenth century the reputation of Calculator was such that Leibniz on several occasions referred to him as almost the first to apply mathematics to physics and as one who introduced mathematics into philsophy.
^Duchesneau, François (1998) "Leibniz's Theoretical Shift in the Phoranomus and Dynamica de Potentia", Perspectives on Science 6, p. 105.