Leonard Peikoff discusses communication in the form of argument or informal debate. In this lesson, you’ll consider such issues as the goals of arguing, when to argue, why you should not argue with a dishonest opponent and how to judge your opponent’s intellectual honesty. Peikoff explains how to argue effectively by using “philosophical detection” to uncover your opponent’s fundamental premises, answer your opponent’s essential points and use techniques to deal with spurious “facts.” He also stresses the importance of self-evaluation and practice. The lesson concludes with two practice arguments and an analysis of them based on the principles discussed.