James Buchanan (1804-1870) was a Scottish minister and theologian who joined the Free Church of Scotland in 1843 and succeeded Thomas Chalmers as professor of systematic theology at New College, Edinburgh, in 1847, a post he held for twenty-one years.

His magnum opus was The Doctrine of Justification, which retains great value as a classic treatment of the article by which, Luther said, the church stands or falls. Buchanan covers the history of the doctrine as well as its exposition, which is what distinguishes the work: a reader sees both what Scripture teaches and how the church came to state it. Hardcover.