The British biologist, philosopher, and psychologist Conwy Lloyd Morgan is widely regarded as one of the founders of comparative psychology. He is especially well known for his eponymous canon, which aimed to provide a rule for the interpretation of mind from behavior. Emphasizing the importance of the context in which Morgan was working—one in which casual observations of animal behavior could be found in Nature magazine every week and psychology itself was fighting for scientific legitimacy—I provide an account of Morgan’s (...) vision for the comparative psychologist qua professional psychologist. To this end, I explore the important connection between Morgan and the evolutionary theorist, philosopher, and psychologist Herbert Spencer. It is from Spencer, I contend, that Morgan inherited a number of his key epistemological and methodological concerns about the nascent science of comparative psychology. This extends all the way to the canon, which only works as intended when paired with a Spencerian understanding of mental evolution as a progressive linear sequence. Far from being an incidental residue of a pre-Darwinian time, hierarchy was intentionally built into the very core of Morgan’s scientific comparative psychology. (shrink)