The Henry Waldgrave Stuart Professor of Philosophy at Stanford University, John Perry, spoke in Taylor Hall on "Language and the Flow of Information," as part of the annual Philosopher's Holiday lecture series.  A scholar of the philosophy of language, logic, information and metaphysics, Perry frequently drew attention to the strengths and limitations of language to inform. Among his numerous works were his 1978 dialog between a mortally wounded university professor and her two friends, A Dialog on Personal Identity and Immortality (1978), his humorous online essay Structured Procrastination (1995) and the collection of essays The Problem of the Essential Indexical (1993), the title essay of which begins with Perry’s discovery in a supermarket that the trail of spilled sugar he has been following is coming from his own cart.

“I believed at the outset that the shopper with a torn sack was making a mess.  And I was right.  But I did not believe that I was making a mess.  That seems to be something I came to believe.  And when I came to believe that, I stopped following a trail around the counter and rearranged the torn sack in my cart.  My change in beliefs seems to explain my change in behavior….

“At first, characterizing the change seems easy.  My beliefs changed, didn’t they, in that I cam to have a new one, namely, that I am making a mess.  But things are not so simple.

“The reason they are not is the importance of the word ‘I’ in my expression of what I came to believe.  When we replace it with other designations of me, we no longer have an explanation of my behavior and so, it seems, no longer an attribution of the same belief.  It seems to be an essential indexical.”     John Perry, The Problem of the Essential Indexical

John Perry and his Stanford colleague, Professor of Philosophy Ken Taylor, founded the hour-long weekly radio program, “Philosophy Talk”—“The program that questions everything…except your intelligence.”—in the fall of 2003.