Comments on “What can you believe?”

Thanks… that’s another “can’t be bothered to fight the software right now.” Somehow every couple years I am forced to switch to a different drawing program, and they all do the same things, but hide the functionality in a deep swamp of menus and panels and config options, so producing a simple diagram with the most recent one will take me hours to find “how do I make this line spliney?”

Is a model of belief and truth just a set of propositions?

“Model” is rather vague, so there’s no definite answer here. However, “theory” is sometimes used specifically to mean a set of propositions, and I try to use that word with that meaning consistently. Rationalist explanations of truth do try to be theories in this sense. (This is one way in which rationalism tries to be a rational theory of rationality.) In fact, rationalist models mostly fail to be theories, because beliefs aren’t propositions, and you can’t make a theory work starting from that wrong assumption.

The outstanding example of a rationalist model of belief and truth that is a theory is model theory. That’s a beautiful piece of mathematics, and in some sense it is the rationalist theory of belief and truth. However, no one uses it outside the narrow field of mathematical logic, because it fails to capture most of what we understand about its informal subject matter.

If so, what sense does it make to talk about abandoning them if the idea of propositions is taken as incoherent?

Propositions are an artificial construct that are made necessary only because rationalist theories take abstract universal beliefs as the prototypical case. (Taking “propositions” here in the technical sense of the word, as opposed to a vague, informal meaning like “things people say.”)

Relevant here is the explanation of three types of explanations in “Accounts, theories, and understandings.” Inasmuch as this book aims to explain belief and truth, it offers meta-rational understandings of them, rather than rational theories. Meta-rational understandings do not involve propositions (in the technical sense of that word). They mostly don’t even center “claims” or “assertions” (although those may be involved). Understanding (in terms of ontological distinctions) is prior to anything that could be true or false. (Using “true” and “false” informally here.)