Reasoning from Paradigms and Negative Evidence
Universidade Nova de Lisboa
August 11, 2011
Pragmatics & Cognition, Vol. 19, No. 1, pp. 92–116, 2011
Reasoning from negative evidence takes place where an expected outcome is tested for, and when it is not found, a conclusion is drawn based on the significance of the failure to find it. By using Gricean maxims and implicatures, we show how a set of alternatives, which we call a paradigm, provides the deep inferential structure on which reasoning from lack of evidence is based. We show that the strength of reasoning from negative evidence depends on how the arguer defines his conclusion and what he considers to be in the paradigm of negated alternatives. If we negate only two of the several possible alternatives, even if they are the most probable, the conclusion will be weak. However, if we deny all possible alternatives, the reasoning will be strong, and even in some cases deductively valid.
Number of Pages in PDF File: 21
Keywords: argumentation, argument from ignorance, burden of proof, classification under lack of knowledge, defeasible reasoning, Gricean maxims, lack of evidence, negation, scalar predicates
Date posted: August 11, 2011