This text is a transcription of a full course, including both lectures and student discussions, taught by McKeon. As such, it provides an introduction to McKeon's conception of pluralism, a central aspect of neo-Pragmatism, while demonstrating how pluralism works in a classroom setting. In his lectures, McKeon outlines the history of Western thinking on the sciences. Treating the central concepts of motion, space, time and cause, he traces modern intellectual debates back to the ancient Greeks, notably Plato, Aristotle, Democritus and the Sophists. As he brings the story of Western science up to the 20th century, he uses his fabled semantic schema to uncover ideas and observations about cosmology, mechanics, dynamics and other aspects of physical science. Illustrating the broad historical sweep of the lectures are a series of discussions which give detail to the course's intellectual framework.