James Gregory's work laid the foundation for the development of calculus, and his work in astronomy and optics for astronomical observations influenced the works of Isaac Newton. He was born in Drumoak, Scotland, the son of John Gregory, a minister, and Janet Anderson Gregory. Gregory was a sickly child, and his mother guided his early education at home; she must have been an unusual woman for the 17th century, because she included geometry among the subjects she taught her son.

In 1651, Gregory left home for grammar school in Aberdeen, Scotland. He completed his preparatory work, then graduated from Aberdeen's Marischal College, where he focused his studies in mathematical optics and astronomy. Frustrated by the lack of scholarly opportunities in Aberdeen, Gregory traveled to London in 1662, where he met Robert Moray, an influential member of the Royal Society. In 1663, Gregory published Optica promota, a work that anticipated Newton's efforts...