The following four steps are an efficient way to apply what you learned in this chapter—in other words, to evaluate your argument and overcome any errors in validity or truth that it may contain.
1. State your argument fully, as clearly as you can. Be sure to identify any hidden premises and, if the argument is complex, to express all parts of it.
2. Examine each part of your argument for errors affecting truth. (To be sure this examination is not perfunctory, play devil’s advocate and challenge the argument, asking pointed questions about it, taking nothing for granted.) Note any instances of either/or thinking, avoiding the issue, overgeneralizing, oversimplifying, double standard, shifting the burden of proof, or irrational appeal. In addition, check to be sure that the argument reflects the pro and con arguments and is relevant to the scenarios you produced earlier. (See Chapter 9.)
3. Examine your argument for validity errors; that is, consider the reasoning that links conclusions to premises. Determine whether your conclusion is legitimate or illegitimate.
4. If you find one or more errors, revise your argument to eliminate them. The changes you will have to make in your argument will depend on the kinds of errors you find. Sometimes, only minor revision is called for—the adding of a simple qualification, for example, or the substitution of a rational appeal for an irrational one. Occasionally, however, the change required is more dramatic. You may, for example, find your argument so flawed that the only appropriate action is to abandon it altogether and embrace a different argument. On those occasions, you may be tempted to pretend your argument is sound and hope no one will notice the errors. Resist that hope. It is foolish as well as dishonest to invest time in refining a view that you know is unsound.
To illustrate how you would follow these steps, we will now examine two issues.