This document provides introductions to political science, economics, and public policy. It defines political science as the study of the state, nation, government, and politics, with a focus on power at different levels. It notes political science overlaps with but is distinct from political philosophy. The document also defines public policy as examining the passage and implementation of government policies related to areas like civil rights and the environment. Finally, it provides a brief introduction to economics as a social science, but does not provide details on its definition.