Brief outline of his life.

Passage from the Cambridge History of English and American Literature, discussing this Scottish thinker in context.

Biographical article, with bibliography and links, from the MacTutor History of Mathematics.

Article by Savina Tropea, from the Thoemmes Dictionary of Nineteenth-Century British Philosophers. Describes his life, career, and philosophical contributions.

Brief article from the Internet Encyclopedia of Philosophy, covering this Scottish scholar's life and views.

Concise profile from the Hamilton National Genealogical Society.