Reading: Philosophical Arguments

Argument

The word “argument” can be used to designate a dispute or a fight, or it can be used more technically. The focus of this article is on understanding an argument as a collection of truth-bearers (that is, the things that bear truth and falsity, or are true and false) some of which are offered as reasons for one of them, the conclusion. This article takes propositions as the primary truth bearers (definition of proposition: a statement one can accept or reject as true). The reasons offered within the argument are called “premises”, and the proposition that the premises are offered for is called the “conclusion”. Arguments, as understood in this article, are the subject of study in critical thinking and informal logic courses in which students usually learn, among other things, how to identify, reconstruct, and evaluate arguments given outside the classroom.

The characterization of argument in the first paragraph requires development since there are forms of reasoning such as explanations which are not typically regarded as arguments even though (explanatory) reasons are offered for a proposition. Two principal approaches to fine-tuning this first-step characterization of arguments are what may be called the structural and pragmatic approaches. The pragmatic approach is motivated by the view that the nature of an argument cannot be completely captured in terms of its structure. In what follows, each approach is described, and criticism is briefly offered.  Along the way, distinctive features of arguments are highlighted that seemingly must be accounted for.

1. The Structural Approach to Characterizing Arguments

Not just any group of propositions qualifies as an argument. The starting point for structural approaches is the idea that the premises of an argument are reasons offered in support of its conclusion.

Typically in presenting an argument, a person will use expressions to flag the intended structural components of her argument. Typical premise indicators include: “because”, “since”, “for”, and “as”; typical conclusion indicators include “therefore”, “thus”, “hence”, and “so”. Note well: these expressions do not always function in these ways, and so their mere use does not necessitate the presence of an argument.

Suppose that a person we will call Robert offers [1] and [2] as reasons in support of [3]. The argument is presented in what is called standard form; the premises are listed first and a solid line separates them from the conclusion, which is prefaced by “∴”. This symbol means “therefore”. Premises [1] and [2] are convergent because they do not support the conclusion independently of one another. Which means that the two reasons need each other to lend support to the conclusion. It is unreasonable to think that Robert offers [1] and [2] individually, as opposed to collectively, as reasons for [3]. The following representation of the argument depicts the convergence of the premises.

Combining [1] and [2] with the plus sign and underscoring them indicates that they are convergent. The arrow indicates that they are offered in support of [3].

2. The Pragmatic Approach to Characterizing Arguments

The pragmatic approach is motivated by the view that the nature of an argument cannot be completely captured in terms of its structure. In contrast to structural definitions of arguments, pragmatic definitions ask us to look at the function of arguments. Different accounts of the purposes arguments serve generate different pragmatic definitions of arguments. The following pragmatic definition appeals to the use of arguments as tools of rational persuasion.

A collection of propositions is an argument if and only if there is a person Robert who puts forward some of the propositions (the premises) as reasons in support of one of the propositions (the conclusion) in order to rationally persuade an audience of the truth of the conclusion.

One advantage of this definition over the previously given structural one is that it offers an explanation for why arguments have the structure they do. In order to rationally persuade an audience of the truth of a proposition, one must offer reasons in support of that proposition. The appeal to rational persuasion is necessary to distinguish arguments from other forms of persuasion such as threats. One question that arises is: What obligations does a person incur by virtue of offering supporting reasons for a conclusion in order to rationally persuade an audience of the conclusion? One might think that such a person should be open to criticisms and obligated to respond to them persuasively.  By appealing to the aims that arguments serve, pragmatic definitions highlight the methods used by a person when presenting an argument in addition to the arguments themselves.

For example, the acts of explaining and arguing—in sense highlighted here—have different aims.  Whereas the act of explaining is designed to increase the audience’s comprehension, the act of arguing is aimed at enhancing the acceptability of a standpoint. This difference in aim makes sense of the fact that in presenting an argument the person giving the reasons believes that her standpoint is not yet acceptable to her audience, but in presenting an explanation the person knows or believes that the conclusion is already accepted by her audience 

3. Deductive and Inductive Arguments

Arguments are commonly classified as deductive or inductive A deductive argument is an argument that Robert (as our example of a person presenting an argument) puts forward as valid. For a valid argument, it is not possible for the premises to be true with the conclusion false. That is, if the premises are true, then, by necessity, the conclusion is true. Thus we may say that the truth of the premises in a valid argument guarantees that the conclusion is also true. The following is an example of a valid argument: Tom is happy only if his favorite team wins, the team lost; therefore, Tom is definitely not happy.

An inductive argument is an argument that Robert puts forward as inductively strong. In an inductive argument, the premises are intended only to be so strong that, if they were true, then it would be unlikely, although possible, that the conclusion is false. If the truth of the premises makes it unlikely (but not impossible) that the conclusion is false, then we may say that the argument is inductively strong. The following is an example of an inductively strong argument: 97% of the Republicans in town Z voted for McX, Jones is a Republican in town Z; therefore, Jones voted for McX.

In an argument like this, Robert often will conclude "Jones probably voted for McX" instead of "Jones voted for McX," because they are signaling with the word "probably" that they intend to present an argument that is inductively strong but not valid.

In order to evaluate an argument it is important to determine whether or not it is deductive or inductive. It is inappropriate to criticize an inductively strong argument for being invalid. Based on the above characterizations, whether an argument is deductive or inductive turns on whether the arguer intends the argument to be valid or merely inductively strong, respectively. Sometimes the presence of certain expressions such as ‘definitely’ and ‘probably’ in the above two arguments indicate the relevant intensions of Robert. Charity dictates that an invalid argument which is inductively strong be evaluated as an inductive argument unless there is clear evidence to the contrary.

4. Conclusion

A group of propositions constitutes an argument only if some are offered as reasons for one of them. Two approaches to identifying the definitive characteristics of arguments are the structural and pragmatic approaches. On both approaches, whether an act of offering reasons for a proposition P yields an argument depends on what the person believes regarding both the truth of the reasons and the relationship between the reasons and P. A typical use of an argument is to rationally persuade its audience of the truth of the conclusion. To be effective in realizing this aim, the person must think that there is real potential in the relevant context for her audience to be rationally persuaded of the conclusion by means of the offered premises. What, exactly, this presupposes about the audience depends on what the argument is and the context in which it is given. An argument may be classified as deductive, or inductive. Its classification into one of these categories is a prerequisite for its proper evaluation.

The material in this essay was excerpted from a much longer article written by Matthew McKeon, Michigan State University
see  http://www.iep.utm.edu/argument/