This essay explains William James’s (1842-1910) conception of happiness. While much has been written about James's conception of emotions, surprisingly, little has been written about James's conception of happiness. The few scholars who have addressed James’s conception of happiness have either failed to provide the appropriate context or have taken too narrow of a view of the matter. This essay combines a close reading of The Varieties of Religious Experience (1902) with examples from James's personal life to demonstrate that James developed a functionalist conception of happiness. James believed that unhappiness motivates the individual to adopt new mental habits and transform themselves until they can regain their happiness. This framework permits a considerable degree of flexibility, plurality, and experimentation. Although James believed that some strategies worked better than others, he was open to the possibility that individuals could attain happiness by many means.