Behavioral and Brain Sciences

Open Peer Commentary

Classical logic, conditionals and “nonmonotonic” reasoning

Nicholas Allotta1 and Hiroyuki Uchidaa1

a1 Department of Linguistics, University College London, London WC1N 1PF, United Kingdom.


Reasoning with conditionals is often thought to be non-monotonic, but there is no incompatibility with classical logic, and no need to formalise inference itself as probabilistic. When the addition of a new premise leads to abandonment of a previously compelling conclusion reached by modus ponens, for example, this is generally because it is hard to think of a model in which the conditional and the new premise are true.

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