Michael Lynch’s _Truth as One and Many_ on Domain Logical Pluralism

February 26, 2018

~1500 words, ~1200 w/o footnotes

Recently I was looking through Lynch’s book on truth, Truth as One and Many. I was interested in its chapter-long discussion of domain-specific logical pluralism. There he writes about the natural idea that different logics should apply in different domains: say, intuitionism in moral or mathematical domains, but classical logic when talking about physical objects.

I wanted to see what he thought about what we ought to do in the case of sentences mixed across domains. For example, a disjunction might have its first disjunct from one domain and one logic but its second from another. (The logics might disagree about how to handle \lor , after all.)

Here’s his idea (and, what this whole post is about):

where a compound proposition or inference contains propositions from distinct domains, the default governing logic is that of the compound or inference’s weakest member. (100)

Read the rest of this entry »