An effective topic for a persuasive speech shares some characteristics with an informative one: it should be something that you’re interested in, that you know something about, and that is specific enough that you can find a variety of appropriate sources on the topic but not so specific that you can’t possibly develop it. When your purpose is to persuade, however, you must also keep a few other points in mind.

First, your topic should be one that people could have reasonable disagreement about or resistance to. Issues such as human cloning, immigration reform, and government wiretapping lend themselves to a persuasive purpose because people hold strongly differing opinions about them. Second, the topic must allow the speaker to develop a message intended to cause some degree of change in the audience. For example, the topic of mandatory smoking bans could seek changes from different audiences who hold very different views: encouraging action (a change in behavior) from people who already agree that smoking should be banned in public or seeking a change in the attitudes of smokers who currently see no problem with smoking in public places.

Once you have determined that a particular topic interests you and can be persuasive, it’s time to think about developing your thesis statement. In a persuasive speech, thesis statements are often given as a proposition, or a statement about your viewpoint or position on an issue. There are three types of propositions that we will examine: propositions of fact, propositions of value, and propositions of policy.