This dissertation puts forward a series of theoretical proposals aimed to advance our understanding of cognitive kinds. The first chapter introduces the general debates that provide the philosophical underpinnings for the topics addressed in each of the following chapters. Chapter two compares and distinguishes between modules of the mind and mechanisms-as-causings, arguing that they should not be conflated in cognitive science. Additionally, it provides a novel “toolbox” model of accounts of mechanisms, and discusses what makes any such account adequate. Chapter three addresses the question of whether there is a role within the new mechanistic philosophy of science for representations. It advances a proposal on how to carve working entity types, so that they may include representational explanans. Chapter four offers an account of mental disorders, one that captures the regulative ideal behind psychiatry’s inclusion of certain conditions as psychopathologies. Mental disorders are alterations in the production of some mental outputs (e.g. behaviors, beliefs, emotions, desires), such that their degree of reasons-responsiveness is extremely diminished with respect to what we would folk-psychologically expect it to be.