Was born near Kirkmichael in Ayrshire to a deeply religious family. After schooling, he studied first at the University of Glasgow and then at the University of Edinburgh, where he studied under Sir William Hamilton and was awarded an MA for a thesis on stoicism. In 1834 McCosh became a Church of Scotland minister, serving first in Arbroath and then in Brechin. During the Disruption of 1843 he sided with the Free Church of Scotland and became the minister of Brechin's East Free Church. A major change of direction followed in 1851, when McCosh was appointed Professor of Logic and Metaphysics at Queen's College, Belfast. In 1868 he was invited to become President of the College of New Jersey (now Princeton University). He served as President for two years and then stayed on to teach philosophy, which he continued to do until his death in 1894. McCosh is remembered at Princeton in the name of McCosh Hall, the home of the English Department, and in the name of a cross-campus walkway. The university infirmary is named after his wife, Isabella McCosh. Philosophically, McCosh continued the common-sense approach of Thomas Reid and others, believing that the real world was pretty much what it seemed. In the sphere of moral philosophy, McCosh tried to reconcile evolution and Christian beliefs. He argued that evolution, far from being inconsistent with a belief in divine design, was evidence of it. Many who wished to avoid having their beliefs challenged found his approach helpful in allowing religious beliefs to coexist with the rapid development of scientific ideas.