In addition to making a three-pronged distinction between the methods of arguing, Thank You for Arguing draws another important distinction between the different “tenses” in which an argument takes place. Aristotle hypothesized that all arguments fall into one of three categories: forensic rhetoric, which is concerned with blame, and which usually takes a past-tense view of the world; demonstrative rhetoric, which is concerned with values, and which usually takes a present-tense view; and deliberative rhetoric, which is concerned with choices and decisions, and which takes a future-tense. While Aristotle named three different kinds of arguments, Heinrichs is most interested in the latter two. He shows that many of the most frustrating elements of an argument—and, in general, the reason why so many people hate arguing—arise from confusion over the correct “tense” for the argument. Or, to put it another way, the confusion, exasperation, and ignorance of arguing in 21st century America arise from a conflict between demonstrative and deliberative rhetoric.
Early on, Thank You for Arguing points out that the vast majority of arguments are never truly won or lost. Often, this is because the two arguing parties choose to focus on demonstrative rhetoric, the rhetoric of values, when they should be moving to deliberative rhetoric, the rhetoric of choices. Most of the time, it’s difficult, if not impossible, to win a demonstrative debate. In such a debate, both sides argue on behalf of their values or moral convictions; for example, Heinrichs claims that the debate over abortion has devolved into a debate between two sets of moral values: the Judeo-Christian language of life, and the secularized language of freedom. While it’s certainly possible to have a productive demonstrative debate about values and beliefs, politicians debating abortion tend to argue past one another. Similarly, when two people argue over their tastes or opinions, there usually isn’t enough time for them to reach any kind of conclusion.
For both conceptual and practical purposes, then, it’s often a good idea to nudge a debate away from the demonstrative and toward the deliberative—in other words, away from a language of values and towards a language of choices. By changing the scope of the debate from the present to the future, a talented rhetorician can gain control over the argument and win an important tactical victory over an opponent. Even setting aside these strategic concerns, however, Thank You for Arguing suggests that switching from the demonstrative to the deliberative is the most useful, productive move: When people talk about actions and decisions, rather than eternal, unchanging values, they’re more likely to make compromises. In part, this is because talking in the future tense is inherently uncertain, meaning that people are more likely to hedge on their choices, even if they wouldn’t hedge on their values. Furthermore, talking about choices is an inherently practical matter, meaning that people are forced to discuss the implementation of their values in the real world, which often involves compromises and meeting the other side halfway. In all, deliberative argument is far more likely to reach a compromise—and, therefore, a conclusion—than demonstrative argument.
Heinrichs certainly isn’t suggesting that deliberative rhetoric is preferable to demonstrative rhetoric—in fact, he makes it clear that there can be no discussion of choices and actions without some guiding beliefs behind them. However, he emphasizes again and again that the purpose of good rhetoric should be to reach a conclusion of some kind; in order to do so, we need deliberative rhetoric. Especially in the world of politics, where debates too often get bogged down in competing sets of values, rhetoric could play a major role in moving the debate forward and, ultimately, getting things done.