1.4 An Overview of Major Tools

Almost all reasonable arguments, even the simplest, require the use of three basic tools. We will be discussing each of these in more detail later, but for the time being you should make sure you have a firm grasp of the general meaning of each of these.

The first essential tool is clear definition of the basis of the argument (e.g., what is under dispute) and of all terms central to the argument. Obviously, if the parties to the dispute have different notions of what they are arguing about or of what key terms mean, then they will end up arguing about different things (what is called arguing at cross purposes). So an essential part of most arguments is clarifying exactly what you mean. For instance, in the second example above, a key term requiring definition is better runner. Until we define that term much more precisely, we cannot proceed intelligently to deal with the argument.

Clear definition is usually straightforward enough, but, as we shall see, it can present particular problems, especially if a key term has competing definitions (e.g., rival definitions of a foetus are central to debates on abortion, just as rival definitions of death and right are central to debates about the right to die). And a major source of confusion in student essays is often the fact that the writer does not initially define what the argument is claiming. Such a mistake is often lethal to the rest of the essay (more about that later).

The second essential tool is something called deductive reasoning or deduction. This is a logical process by which we move from something we already all agree to be true to the application of this general truth to a particular case (e.g., Killing people is always wrong; capital punishment involves killing people; therefore, capital punishment is always wrong). We use deduction every time we begin the argument with something about which there is general agreement and then interpret a particular example in the light of that general truth (as in geometric proofs, for instance, which always start with an appeal to what already has been proven or agreed to as true).

The general truth we begin with in deductive reasoning must be something we all agree on (its validity must be established prior to the argument). If it is not, then the deductive argument cannot proceed effectively. In some deductive arguments, especially in science, the general truth we agree on may be hypothetical; in other words, we provisionally agree upon something in order to make predictions on the basis of it and then to test the predictions.

Making correct deductions is not always easy, for there are a number of pitfalls (we will be looking at some of them later). However, you need at this point to recognize that any argument which starts from a shared assumption about the truth of a general principle is a deductive argument and that the persuasiveness of the argument is going to depend, in large part, on the shared truth of that general principle.

Finally, the third tool of reasoning is called inductive reasoning or induction. This is the logical process in which we proceed from particular evidence to a conclusion which, on the basis of that evidence, we agree to be true or probably true. Such thinking is also often called empirical reasoning or empiricism. It requires evidence (facts, data, measurement, observations, and so on).

Induction is the basis of a great deal of scientific and technical arguments, those involving the collection of information and the creation of conclusions based upon that information. And it is the basis for most literary interpretation, historical analysis and argument, and so on. Any argument which relies for the persuasiveness of its conclusion on collections of data, on measurement, on information collected somehow (rather than on a general principle) is an inductive argument.

Most of your undergraduate courses spend a good deal of time dealing with induction, instructing you what counts as evidence in a particular discipline, how one sets about collecting and classifying it (laboratory or field procedures, methods of reading literature), and what conclusions one is entitled to derive from it.