How do we acquire knowledge about the world? We will provide an intellectual history of this question, situating it in a historical context by discussing key ideas of philosophers. We will then discuss how scientists and engineers approach this question through model building. We will conclude with discussion of how intelligence relates to understanding and controlling the environment. This course will attempt to provide an overview of various perspectives on this problem that may be interesting to people interested in science who would like to understand the pursuit of knowledge as a humanistic endeavor as well as those interested in philosophy who would like to understand how scientists and engineers develop knowledge.