Skip to main content

What is "Modal Realism"?

Image result for goats in pajamas

One of the Big 30 of philosophy in the list I presented yesterday, perhaps the least well known of them to non-philosophers, is D.K. Lewis. More fully, that is David Kellogg Lewis (1941-2001). He is hanging on at the end of the list, #30, but he is there, in the elite company, nonetheless.

He got there, interestingly, because of a late surge in what one may call pro-metaphysics votes in the polling. The earlier votes had had more of a positivist slant to them. This late pro-metaphysics surge not only got Lewis onto the list it put Aristotle at the top and moved Hegel up (past Nietzsche) to #17.

So let's talk a little about Lewis's defining idea. He is considered the outstanding exponent of extreme modal realism. Let's break that down: (1) modal logic is the branch of logic that addresses issues of possibility and necessity; (2) modal realism is the view that what are called "possible worlds" are real facts; Lewis' extreme modal realism is the view that every other possible world is as real and concrete a fact as this actual world is, and that they appear to be less so only because of some word magic -- "actuality" is indexical.

What is "indexical"? Let's chase the rabbit of definitions a bit further. A concept is indexical if it depends upon where the speaking is standing. Thus, "here" is indexical. I call my friend, at whose home I was recently a guest, and say, "Oh my gosh, I've lost my watch!" He says, "Relax, it's here."

I know the meaning of the word "here," so I know that my watch is at my friend's home. It isn't at MY "here"!

Likewise, "now" is indexical. If I say at the right moment "the sun is now rising" it'll be true. If I wait too long to say it, it'll be false.

Likewise of course the pronoun "I" is indexical.

Lewis's defining idea is that the difference between the actual and any possible world is merely indexical. The world in which goats (like the fellow portrayed above) talk, and for that matter speak fluent French, is as real as this one, it is simply not the one that I am in.

Now you see, I hope, why the pro-metaphysics surge was necessary to lift his name up into our top-thirty.

It is fun to think about, but extreme modal realism has not caught on. It has become more of a lighthouse warning of the rocks than a welcoming beacon.

Why did Lewis believe in modal realism? We'll save that for another day.
Labels:

Comments

Post a Comment

Popular posts from this blog

A Story About Coleridge

This is a quote from a memoir by Dorothy Wordsworth, reflecting on a trip she took with two famous poets, her brother, William Wordsworth, and their similarly gifted companion, Samuel Taylor Coleridge.   We sat upon a bench, placed for the sake of one of these views, whence we looked down upon the waterfall, and over the open country ... A lady and gentleman, more expeditious tourists than ourselves, came to the spot; they left us at the seat, and we found them again at another station above the Falls. Coleridge, who is always good-natured enough to enter into conversation with anybody whom he meets in his way, began to talk with the gentleman, who observed that it was a majestic waterfall. Coleridge was delighted with the accuracy of the epithet, particularly as he had been settling in his own mind the precise meaning of the words grand, majestic, sublime, etc., and had discussed the subject with William at some length the day before. “Yes, sir,” says Coleridge, “it is a majesti
7 comments
Read more

Five Lessons from the Allegory of the Cave

  Please correct me if there are others. But it seems to be there are five lessons the reader is meant to draw from the story about the cave.   First, Plato  is working to devalue what we would call empiricism. He is saying that keeping track of the shadows on the cave wall, trying to make sense of what you see there, will NOT get you to wisdom. Second, Plato is contending that reality comes in levels. The shadows on the wall are illusions. The solid objects being passed around behind my back are more real than their shadows are. BUT … the world outside the the cave is more real than that — and the sun by which that world is illuminated is the top of the hierarchy. So there isn’t a binary choice of real/unreal. There are levels. Third, he equates realness with knowability.  I  only have opinions about the shadows. Could I turn around, I could have at least the glimmerings of knowledge. Could I get outside the cave, I would really Know. Fourth, the parable assigns a task to philosophers
Post a Comment
Read more

Searle: The Chinese Room

John Searle has become the object of accusations of improper conduct. These accusations even have some people in the world of academic philosophy saying that instructors in that world should try to avoid teaching Searle's views. That is an odd contention, and has given rise to heated exchanges in certain corners of the blogosphere.  At Leiter Reports, I encountered a comment from someone describing himself as "grad student drop out." GSDO said: " This is a side question (and not at all an attempt to answer the question BL posed): How important is John Searle's work? Are people still working on speech act theory or is that just another dead end in the history of 20th century philosophy? My impression is that his reputation is somewhat inflated from all of his speaking engagements and NYRoB reviews. The Chinese room argument is a classic, but is there much more to his work than that?" I took it upon myself to answer that on LR. But here I'll tak
13 comments
Read more