Practical reasoning is a goal-directed sequence of linked practical inferencesthat seeks out a prudent line of conduct for an agent in a set of particular circumstances known by the agent. Where a is an agent, A is an action, and G a goal, thetwo basic types of practical inferences are respectively, the necessary conditionscheme and the sufficient condition scheme (Walton, Pract. Reas., 1 990; see alsoSchellens, 1 987).G is a goal for aDoing A is necessary for a to carry out GTherefore, a ought to do AG is a goal for aDoing A is sufficient for a to carry out GTherefore, a ought to do A

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).