Political theory is about ideas, including freedom, equality, and justice. Political ideas matter because we act on them; they inform our institutions of governance. They matter too because we debate our future using them; they tell us what is to be done. By the end of this course, you should have a better grasp of the ideas that inspired the world in which we live and the ideas that might direct our future. To be effective, political theories have to contain ideas that support one another in wider webs. Ideologies are examples of webs of political ideas, containing ideas about what the world is like, why it is as it is, and what it might become. After a brief examination of the nature of political theory and ideology, we will study the main ideologies found in contemporary political debate: liberalism, conservatism, socialism, nationalism, feminism and environmentalism.