Skip to content


Episode 36: Robert van Rooij discusses vagueness

This month we’re joined by Robert van Rooij, Assistant Professor of Philosophy of Language at the Institute for Logic, Language, and Computation, at the University of Amsterdam.  Click here to listen to our conversation with him.

As it happens, nearly everything we say is imprecise.  For example, when I indicate where I want you to stand while posing for a photo, I don’t give exact coordinates; I just point with my finger.  When I tell you my friend Janine is really tall, I don’t specify her height right down to the last millimeter.  Would six feet count as tall?  Probably.  How about 5’11″?  Or 5’10″?  5’9″?  The closer we get to the middle of the boundary between people who are tall and people who aren’t, the more of a challenge it is to say, because the boundary is blurry.  And when I tell you that my sixth grade music teacher was bald, it isn’t clear exactly how much hair I’m saying he had.  Maybe he had absolutely no hair, or maybe he had a little bit.  In any event, he didn’t have much.  But how much does it take to be ‘much’?  What are we to make of the fact that we can’t give an exact answer to that question?

Now that you’re here, try the following little experiment with your computer screen.  Here is a set of colors that proceed gradually from red to orange.  Try to decide which is the last of the red squares, and which is the first of the orange squares.  If you’ve got a friend in the room with you, see what they think.

The upper left-hand square is definitely red, and the bottom right-hand square is definitely orange.  But as for the rest, their status is kind of up in the air.  On the one hand, none of the changes from any individual square to the next suffice to turn one color into another.  Each change, taken on its own, is insignificant.  And yet somehow, after we apply enough of these minute changes in succession, they eventually add up to something quite significant.  That’s what’s so perplexing about vagueness.

Should we be discouraged by the fact that just about all the categories we use have blurry boundaries?  Robert van Rooij doesn’t think so.  Tune in to hear a new solution to the paradoxes of vagueness, as well as an explanation for why human language is so imprecise to begin with!

Matt Teichman

Posted in Podcast.


0 Responses

Stay in touch with the conversation, subscribe to the RSS feed for comments on this post.



Some HTML is OK

or, reply to this post via trackback.