William Hamilton, the Scottish philosopher and logician, was born in Glasgow and was educated at Glasgow, at Edinburgh, and at Balliol College, Oxford, where he took his B.A. in 1811. After leaving Oxford he studied law and in 1813 was admitted to the Scottish bar. He was appointed professor of civil history at the University of Edinburgh in 1821 and was elected to the chair of logic and metaphysics in 1836. Hamilton, a man of stupendous erudition, was strongly influenced by Thomas Reid and Immanuel Kant.

Psychology

Hamilton divided "mental modifications, or phenomena" into three classes—the phenomena of knowledge or cognition; the phenomena of feeling, of pleasure and pain; and the phenomena of will or desire, the exertive or connative powers. Knowledge, feeling, and will or desire cannot exist independently of one another. Every state of mind is a combination of all three, although proportions may...