 Alexander Bain was Regius Professor of Logic at the University of Aberdeen from 1860 to 1880. A man of remarkable gifts, he was appointed to the Chair largely on the strength of distinguished philosophical work he had published while working as a journalist in London. It was there that he made the acquaintance of John Stuart Mill with whom he formed a lasting friendship. Dissertations on Leading Philosophical Questions (1903), is a collection of his essays published in retirement, though almost all had originally appeared in the journal Mind, a journal he was instrumental in founding, In several of these essays, Bain takes Reid and Hamilton as his starting point and, broadly, follows the same methods. But, his sympathy with Mill and anti-metaphysical inclinations led him to push them in a much more strongly empirical direction. The most interesting of his Dissertations, in this connection, is entitled “Associationist Controversies” and at the heart of these controversies we can find a distinction between philosophy and psychology that both reveals the significant difference between Bain and Ferrier, and establishes the discipline of experimental psychology in its own right.