Writing Analytically, 6th Edition - Rosenwasser, David & Stephen, Jill.original_ [129]
If a writer follows the prescribed steps of the syllogism without violating any of the rules on proper wording and on the way the steps may be put together, then the conclusion arrived at in step 3 is valid. An argument evaluated in this way can be valid and still be false. For example:
All politicians are corrupt.
The mayor of Chicago is a politician.
Therefore, the mayor of Chicago is corrupt.
The problem here is not with the form of the syllogism but with the fact that the major premise is untrue.
To make good use of syllogistic reasoning, you need to get into the habit of recasting arguments that you write or read or hear into the proper syllogistic form. The way most people articulate claims—often without even recognizing that they are making claims—is rarely if ever syllogistic. Claims, for example, if they are to be most easily assessed for validity, usually need to be recast using forms of “to be” rather than other kinds of verbs (as in the Chicago example above).
While arguments as formulated in formal logic are grounded in abstract, universal terms, most arguments as we encounter them in daily life involve statements about values and beliefs. These real-life arguments typically appear in a form that philosophers call the “enthymeme.” An enthymeme is an incomplete syllogism. One of its premises has been left unstated, usually because the person offering the argument takes the unstated assumption to be a given, something so obviously true that it doesn’t even need to be made explicit.
Sample Enthymeme: Cats make better pets than dogs because cats are more independent.
Unstated Assumption: Independent animals make better pets.
Sample Enthymeme: Charter schools will improve the quality of education because they encourage competition.
Unstated Assumption: Competition improves the quality of education.
TOULMIN’S ALTERNATIVE MODEL OF THE SYLLOGISM
British philosopher Steven Toulmin offered a competing model of argument in his influential book, The Uses of Argument (1958). Toulmin’s model was motivated by his belief that the philosophical tradition of formal logic, with its many rules for describing and evaluating the conduct of arguments, conflicts with the practice and idiom (ways of phrasing) of arguers. To radically simplify Toulmin’s case, it is that the syllogism does not adequately account for what really happens when thinkers try to frame and defend various claims. Toulmin tried to describe the structure of argument in a way that he thought came closer to what actually happens in practice when we try to take a position.
FIGURE 9.1
The Toulmin Model.
The Toulmin model of argument renames and reorders the process of reasoning described in the Aristotelian syllogism as follows:
Data: the evidence appealed to in support of a claim; data respond to the question “What have you got to go on?”
Warrant: a general principle or reason used to connect the data with the claim; the warrant responds to the question “How did you get there?” (from the data to the claim).
Claim: a conclusion about the data (see Figure 9.1).
Consider this model in terms of the chapter’s opening discussion of linking evidence and claims. In the Toulmin model, the warrant is the link. It supplies the reasoning that explains why the evidence (support) leads to the conclusion (claim).
Let’s look briefly at how this reasoning structure works in practice by looking at one of Toulmin’s examples.
data: Harry was born in Bermuda.
warrant: The relevant statutes provide that people born in the colonies of British parents are entitled to British citizenship (reason for connecting data to claim);
claim: So, presumably, Harry is a British citizen. (conclusion)
We can now follow Toulmin a