The thesis of this paper is that an argument's possessing the form of affirming the consequent does not suffice to make its premises at all favorably relevant to its conclusion. In support of this thesis I assume two premises and argue for a third. My two assumptions are these: (1) that an argument's possessing the form of affirming the consequent does not suffice to make its conclusion certain relative to its premises (this is widely, if not universally, acknowledged by writers (...) on logic), and (2) premises are favorably relevant to a conclusion only if it is certain or probable relative to them (I argued for this in an earlier paper). The premise I argue for in this paper is that an argument's possessing the form of affirming the consequent does not suffice to make its conclusion probable relative to its premises. To establish this third premise, I first refute a defense of the contrary position (namely, that an argument's possessing the form of affirming the consequent suffices to make its conclusion probable relative to its premises), then offer counterexamples to that position, and finally demonstrate the failure of several attempts to save it. (shrink)

A methodology of argumentation and a perspective of incredulity are essential ingredients of all intellectual endeavor, including that associated with the art and science of medical care.Traditio argumentum respectus (tradition of respectful argumentation) as a principled system of assessing the validity of beliefs, opinions, perceptions, data, and knowledge, is worthy of practice and perpetuation, because assessments of validity are susceptible to incompleteness, incorrectness, and misinterpretation. Since the latter may lead to ambiguity, uncertainty, anxiety, and animosity among the individuals (patients and (...) physicians) involved in such dialogue, objective analyses and criteria are desirable. A tradition of respectful argumentation is a means to this end—to maximize objectivity and minimize subjectivity as part of decision-making processes and to preserve the integrity of the participants in a patient-physician relationship. During such discourse one must always be cognizant of fallacious arguments—material, verbal, and formal fallacies—since they compromise the validity of assertions. This essay summarizes a classification of fallacious arguments, by definition and by example, predicated upon the intellectual tradition of Occidental Society; and advocates a tradition of respectful argumentation to nullify them. (shrink)