Concept tag
#excluded-middle
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‘With us or against us’ sounds like logic. Is it?
One sentence I've heard in Colombia from armed men of every stripe, and sometimes from people on the other side of the table, is "if you're not with us, you're against us". In villages that wanted nothing to do with any armed…
Started by Andrés Zuluaga4 replies -
If you had to give up one classical principle, which would you choose?
I've been working through a list of non-classical logics, and each one gives up something different: bivalence (every statement true or false), excluded middle (P or not-P), explosion (from a contradiction, anything), or the assumption that every name refers to something. Thought…
Started by Emeka Anyaoha6 replies -
Intuitionists are right to refuse the law of excluded middle for infinite collections
I lean intuitionist, so I declare my bias. Here's the case. For Brouwer, mathematical objects are mental constructions, and to assert that something exists is to be able to construct it. On that view, “P or not-P” is a claim that we…
Started by Ana Clara Ferreira5 replies -
Reading group: Dummett’s ‘The Philosophical Basis of Intuitionistic Logic’
I keep noticing that people defend intuitionistic logic for two very different reasons. Brouwer's reason was a picture of mathematics as mental construction. Dummett's reason, in his 1973 paper "The Philosophical Basis of Intuitionistic Logic", was a theory of meaning. I'd like…
Started by Ana Clara Ferreira5 replies