Joseph Foley, welcome back to the show. Thank you very much for having me. What is logic?

Because no foreplay today, never. Never with us. I suppose like many things in philosophy, it depends who you ask.

So as it's traditionally conceived, sort of going all the way back to Aristotle, logic is supposed to be the most general principles of reasoning such that when you

have a set of stuff you already know or you're already asserting, you can through a series of

indubitable steps get to a further conclusion that follows without any doubt and without any

possibility of being wrong from those things

you initially know. So classic example from Aristotelian logic is all men are mortal. Socrates

is a man. Therefore, Socrates is mortal. And effectively, you know, Aristotle's point here is

that you can't even imagine that being false. There's no situation

where all of the premises are true and the conclusion is false. So you are carried in some sense

from the premises to the conclusion without any kind of possibility for error entering in.

That's kind of the

classic Aristotelian picture. And amongst philosophers, this has remained, I would say,

relatively orthodox right up until maybe the end of the 20th century. And even now, it has

really, really staunched offenders. So this idea that there is a one true

logic, and that's the thing that philosophers are interested in when they talk about logic.

A recent book was put out, recently called the one true logic that was defending this idea

by Owen Griffiths and Alexander Pazzo, I think his name is.

I only remember Owen Griffiths because he supervised my undergrad dissertation,

and he wrote it with this other guy who I'm sure is very, very clever, but I've never met him,

so his name doesn't stick in my mind. But another alternative conception of logic to this

kind of historical orthodoxy, but in the modern day, I would say it's become less orthodox,

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