Renowned primarily for his thoughts about pluralism, it is surprising to note that relatively little attention has been paid to what Isaiah Berlin says about the idea of monism. Usually treated as a prefatory consideration, commentators have tended to gloss Berlin’s thoughts about monism. This is, I believe, a mistake. For when one attends to what Berlin says one notes the various forms of monism in his essays, as well as the different implications of each. Berlin presents monism in different ways according to topic, and thereby highlights different issues. Considering his discussions of monism as regards history, philosophy, and politics allows for a much more nuanced account of Berlin’s position, as well as a better appreciation of what he thinks the problems of monism are.