Applying Soundness Standards to Qualified Reasoning

Robert H. Ennis


Defining qualified reasoning as reasoning containing such loose qualifying words as 'probably,' 'usually,' 'probable, 'likely,' 'ceteris paribus,' and 'primafacie, Ennis argues that typical cases of qualified reasoning, though they might be good arguments, are deductively invalid, implying that such arguments fail soundness standards. He considers and rejects several possible alternative ways of viewing such cases, ending with a proposal for applying qualified soundness standards, which requires employment of sufficient background knowledge, sensitivity, experience and understanding of the situation. All of this takes place as part of the process, introduced elsewhere, of successively applying different legitimate sets of standards until one is found that is satisfied, or none is found, the latter calling for rejection of the argument, the former calling for its acceptance.


deductive validity, soundness, qualified reasoning, nonmonotonic reasoning, probable, probably, argument appraisal strategy, subjective probability, validity, ceteris paribus. prima facie. argument, argument standards, conduction, situation, background knowledge, critical thinking, informal logic

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ISSN: 0824-2577