Clearly this type of reasoning has an argumentation scheme. One premisedefines or describes a goal. The other premise describes a means of achieving thegoal. The conclusion directs the agent towards action to carry out the means.6But this type of reasoning is so common and distinctive, having manyvariants and subspecies of argumentation, that it is misleading to call it anargumentation scheme. Better to call it a type of reasoning that can be used inargumentation in different types of dialogue (as in Walton, What Reas., 1990).

Arguments like the one in Case 1 . 1 lie on a razor's edge: They are somewhatweak and unreliable, and apt to fail occasionally, but they are not so bad or inherently erroneous that they should be called "fallacious" in all instances. On theother hand, they can tum out to be fallacious, in some cases. And, in particular,they run the risk of committing the secundum quid fallacy as quite a general sort offailure they are prone to. If this is right, a new approach to fallacies is called foran approach that takes more care in assessing the particulars of a given case.In arguments like the one in Case 1 . 1 , the premise, if true in a given case,does give a reason for accepting the conclusion. But it is not a conclusive reason,and it is subject to default relative to what is known (or becomes known) of thefurther circumstances of the case. The problem then is to find the underlying structure of inference in such a case that enables one to identify and test the correctness(or incorrectness) of the argument as an instance of an argumentation scheme