Supplements

Much of our last episode dealt with what Aristotle meant by words like ’every’ and ‘some.’ As we discussed at some length in our previous post, in the Aristotelian setting, the meaning of ’every’ was slightly different from what we’re used to. Under today’s meaning of the word ’every,’ when I say ’every frog is green,’ you can check to see whether what I just said is true by checking to see whether the set of frogs is a subset of the set of green things. But in Aristotle’s philosophy, it takes more to make the sentence ’every frog is green’ true. It’s not enough for the set of green things just to contain the set of frogs. ...

In our latest episode, Peter Kail addressed a popular misreading of David Hume’s views about induction—the process of inferring things about the future on the basis of facts about the past. According to this reading, Hume is a skeptic about induction. Let’s distinguish skeptical from non-skeptical views about induction like this: Skepticism about induction: we are never justified in believing things about the future on the basis of facts about the past. ...

Thus far, three of our episodes (12, 25 and 28 have contained some discussion of possible worlds semantics. Most memorably, we learned in our last episode that John Searle is rather critical of the enterprise. But what is possible worlds semantics? Let’s take a look. This possible worlds business originally stems from the work of 17th-century philosopher and polymath, Gottfried Wilhelm Leibniz. Leibniz got the ball rolling on possible worlds by putting forth the idea that a statement is necessarily true just in case it is true in all possible worlds, and possibly true just in case it is true in some possible world. The idea also plays a role in his controversial view that we live in the best of all possible worlds. Leibniz was resolutely mocked for this idea in Voltaire’s Candide. ...

Thus far, a number of our interviews have alluded to what philosophers of language call indexical expressions. (In particular, episodes 12, 25, and 27.) Although the theory of what these words and phrases mean represents one of the major developments in philosophy over the past fifty or so years, it can seem counterintuitive at first. Since the questions these words raise are unusually subtle and difficult, we thought it might be worthwhile to go over some of the basics. ...