Duncan Liddel was born in Aberdeen and died there on 17 December 1613. After receiving his early education in Aberdeen, Liddel departed for the Continent in 1579, where he matriculated in the University of Frankfurt-an-der-Oder. There he studied mathematics, philosophy and medicine for the next six years, interrupted only by a year-long visit to Breslau. When an epidemic struck Frankfurt in 1585, Liddel moved on to the University of Rostock, where he took an MA in 1587. In Rostock he was befriended by several eminent men: the astronomer and professor of medicine Henrich Brucaeus, the famous humanist Johannes Caselius and the young philosopher Cornelius Martini, who was to become one of the key figures in the revival of metaphysics in Lutheran Germany. Probably thanks to Brucaeus, Liddel made the acquaintance of the great astronomer Tycho Brahe, whom he visited at least twice at his observatory in Denmark (June 1587 and June 1588). In 1590 Caselius accepted an invitation to the thriving young University of Helmstedt, where he seems to have been instrumental in the appointment of his two younger protégés, Liddel and Martini, to the chairs of mathematics and logic respectively. In Helmstedt, Liddel completed his medical studies: he received an MD in 1596 and was made Professor of Medicine in 1600 (without relinquishing the chair of mathematics until 1603). In 1607 he returned to Scotland, but of his last years little is known aside from the fact of his generous endowments to Marischal College, Aberdeen.
From The Continuum Encyclopedia of British Philosophy in Oxford Reference.