What are the ontological commitments of cognition? Philosophy of cognition inherits a great deal from philosophy of science in answering this question. In philosophy of science, scientific theories are the basis of predictions and explanations. This course explores how philosophers of cognition are naturally inclined to model cognitive activity on theoretical activity. This is the case for philosophers as far apart on the spectrum as Fodor (1983), Paul (1979) and Patricia Churchland (1986), or Egan (2019). But are there strong arguments to think of cognition as essentially theoretical in character? In this seminar, we will be critically assessing the strength of the arguments to think that cognitive activity as essentially theorising, either in virtue of its being propositional or model-like. To do so, we will focus on the Modularity of Mind, and Bayesian theories of cognition. Within those frameworks, we will consider and think the philosophical puzzles that arise, as well as their explanatory capacity to make best sense of empirical evidence.