In the first session of the seminar "Main Debates in 20th Century Political Thought", professor João Espada presented two main questions: Why did the liberal democracy in Europe collapse? Why did the second world war occurred? He began explaining that before the first world war, the liberal democracy was the normal political regime but then this regimen collapsed. During the second world war some people often thought that Hitler represented capitalist against the socialism of the Soviet Union. Since that time, people has been thinking about the power structure in society and the role of government.

During this session, João Espada explores four authors' views related to free trade, limited government, decentralised decision making, private property and market economy. He analyses the ideas of Friedrich List, who based his writings in the school of Adam Smith and wrote about protected trade, individual economy and public economy. Then he analyses the Communist Manifesto, written by Friedrich Engels and Karl Marx, and explains some topics related to the scientific socialism like iron laws of history, modes of economic production, the bourgeoisie and the class struggle. He mentions Popper's critique to Marx, related to the absence of the moral dimension in his theory. Finally he analyses the ideas proposed by Carl Schmitt related to political parties and a total state.