The appellation "Merton Calculators" is an artificial designation referring principally to four individuals who were students or masters at Merton College, Oxford, in the fourteenth century. Their real link derives from their common interest in developing techniques for solving a variety of logical dilemmas and mathematical problems applicable to natural philosophy and theology. "Calculator" was the name given apparently by fifteenth-century Italian Schoolmen to the chronologically last of these authors, Richard Swineshead, and it has been applied retrospectively to the others. The other principal "Calculators" were William Heytesbury, Thomas Bradwardine, and John of Dumbleton.

Heytesbury's date of birth is a matter of pure conjecture; it must have been before 1313, as he was a doctor in theology by July 1348. He is thought to have been born in Wiltshire in the diocese of Salisbury. He was a fellow at Merton College in 1330, a bursar at Merton in 1338, and apparently a...