Bryan Frances

The Burge-Putnam thought experiments have generated the thesis that beliefs are not fixed by the constitution of the body. However, many philosophers have thought that if this is true then there must be another content-like property. Even if the contents of our attitudes such as the one in ‘believes that aluminum is a light metal’, do not supervene on our physical makeups, nevertheless people who are physical duplicates must be the same when it comes to evaluating their rationality and explaining their actions. I argue that the considerations motivating this view are best handled with just the ordinary ‘that’-clause contents.

In this essay (for undergraduates) I introduce three of the famous semantic paradoxes: the Liar, Grelling’s, and the No-No. Collectively, they seem to show that the notion of truth is highly paradoxical, perhaps even contradictory. They seem to show that the concept of truth is a bit akin to the concept of a married bachelor—it just makes no sense at all. But in order to really understand those paradoxes one needs to be very comfortable thinking about how lots of interesting sentences talk about not dogs or cats or elections or baseball but sentences. That is, we need to get familiar analyzing sentences that talk about sentences.