Tolerant reasoning: nontransitive or nonmonotonic?
Pablo Cobreros, Paul Égré, David Ripley, Robert van Rooij · Synthese · 2017
Abstract The principle of tolerance characteristic of vague predicates is sometimes presented as a soft rule, namely as a default which we can use in ordinary reasoning, but which requires care in order to avoid paradoxes. We focus on two ways in which the tolerance principle can be modeled in that spirit, using special consequence relations. The first approach relates tolerant reasoning to nontransitive reasoning; the second relates tolerant reasoning to nonmonotonic reasoning. We compare the two approaches and examine three specific consequence relations in relation to those, which we call:strict-to-tolerantentailment,pragmatic-to-tolerantentailment, andpragmatic-to-pragmaticentailment. The first two are nontransitive, whereas the latter two are nonmonotonic.