I. Introduction I begin this chapter by introducing the notion of argument, which is central on all accounts to the business of critical thinking. When we craft arguments for particular conclusions, we participate in an exercise that falls under our working definition and so counts as critical thinking. In the course of this discussion, I attend to the nature of argument and arguments, that is, the nature argument understood as a process and as aproduct. With the notion of argument in play, I then argue that critical thinking can be approached as argumentation without loss of anything essential to the subject. If we teach our students to construct and analyze arguments, broadly conceived, we teach our students to think critically. No central critical thinking skill need be left out of an instructional approach that emphasizes argument. I conclude by identifying the four categories associated with the construction and analysis of argument: identification, reconstruction, analysis, and critique. These categories will serve to frame the introduction of critical thinking skills and associated pedagogical strategies in the next chapter. II. Argument and Arguments The term 'argument' is ambiguous. On the one hand, it is an activity that we engage in with others; on the other hand, it is a rationale for some conclusion. Both senses of the term are relevant to our concerns. Students will often find themselves in arguments, and facility with critical thinking skills will certainly aid them as they defend their positions. Further, arguments understood as rationales are a perspicuous vehicle for evaluation of the type that is central to critical thinking; indeed, construction and assessment of such arguments will certainly exercise one's thinking skills. In this section, I develop both senses of 'argument'. II.1 The Process of Argument In one sense, argument is activity. The activity of arguing can be formal and rule-governed, such as in Presidential Debates, or it can be a free-for-all, no-holds-barred event with lots of shouting and gnashing of teeth, or it can be something in between. In all situations it would appear to be purposive, although the purpose might only be to pass the time; beyond this, it isn't clear if there is any one trait that all instances of argumentation share. Typically, although not always, there will be something over which the participants are arguing, viz., some claim or position. (Contrast: an argument in which the participants are confused about what the topic is, or one that arises out of strong emotion without a focal theme.) In those cases where there is a claim or position in dispute, participants contribution to the argument will be designed to establish the superiority of their views. Superiority in such cases need not always be cast in terms of truth; in fact, given that the goal of many arguments is to vanquish the opponent, superiority will generally be granted to the view that prevails. (At least by the one who prevails, that is. Another point is in order here: "vanquishing the opponent" isn't always about making them cry "uncle"; what counts as a vanquished opponent varies from context to context.) Since contributions to arguments are intended in such cases to achieve victory, they might be designed to convince, confuse, overwhelm, or frighten, to name a few. Very often these contributions are delivered as sentences in a conversation, but they needn't take this form. For instance, as anyone in a relationship knows, you can conduct an argument entirely with your eyebrows. While it is true that not all episodes of argumentation involve participants who defend determinant conclusions, it is safe to say that episodes typically do. Restricting our attention for the moment to the typical episode, we can offer a more systematic description of the stages that it involves. First, there is the recognition stage. During this stage, the participants recognize that they have something to argue about. This could be highly conventionalized, as in a formal debate, but it need not be. Recognition of a disputed topic could spring from an explicit difference of opinion, a mutual observation, an opposition of actions or reactions, or even an otherwise innocent remark. In addition to mutual recognition of a disputed issue, there will often be recognition of certain rules that will frame subsequent argumentation. For instance, if it is a formal debate, participants will also recognize the existence of time limits, rules governing interaction and interruption, win-loss rules, etc. If the argument is in discussion in a classroom, there will be rules about proscribed types of language, rules concerned with respect for other discussants, rules about turn taking, etc. Many such rules are attached to the context in which you happen to be when the argument breaks out. We can classify the many types of rules with the help of the following structure, borrowing from Douglas Walton and John Se