In “On the evolution of human motivation: the role of social prosthetic systems,” Stephen Kosslyn makes a very interesting conjecture about social interactions. He argues that, for a given person, “other people serve as prosthetic devices, filling in for lacks in an individual’s cognitive or emotional abilities.” This part seems hard to argue with. Intuitively, we all rely on other people to do certain things for us (mow our grass, edit our papers, provide us with love). His crucial insight is that “the ‘self’ becomes distributed over other people who function as long-term social prosthetic systems.”
You may or may not agree with that stronger claim. I haven’t made up my own mind yet. I recommend reading the paper itself, which unfortunately is not available on his website but should be available in a decent college library.
There is one interesting application of his idea to an old problem in linguistics and philosophy.
What is the problem? Intuitively, we would like to believe that our words pick out things in the world (although words and concepts are not interchangeable, for the purposes of this discussion, they have the same problems). When I say “cows produce milk,” I like to believe that this sentence is either true or false in the world. For this to even be plausible, we have to assume that the words “cow” and “milk” refer to sets of real, physical objects.
This is problematic in myriads of ways. It is so full of paradoxes that Chomsky has tried to define away the problem by denying that words refer to anything in the world. I will focus on one particular problem that is relevant to the Kosslyn conjecture.
If you are like me, you know nothing about rare plants such as the three-seeded mercury or the Nova Scotia false-foxglove. Yet, we are able to have conversations about them. I can tell you that the both are endangered in the state of Maine, for instance. If I tell you that they both survive on pure Boron, you would probably be skeptical. Thus, we can talk about these plants and make empirical claims about them and learn new things about them without having any idea what these words actually pick out in the world. This is true of a large number of things we talk about on a daily basis. We talk about people we have never met and places we have never been.
What distinguishes these words from words that truly have no reference? To you, likely neither the words “Thistlewart” nor the word “Moonwart” mean anything. Now, suppose I tell you the first is a made-up plant, while the second is a real plant. To you, these are still both essentially empty words, except one refers to something in the world (though you don’t know what) and the other doesn’t.
Intuitively, what makes “Thistlewart” an empty concept and “Moonwart” not is that you believe there is some expert who really does know what a Moonwart is and could pick one out of a lineup. This “Expert Principle” has seemed unsatisfying to many philosophers, but within the context of the “social prosthetic system” theory, it seems quite at home. Certainly, it seems like it might at least inform some of these classic problems of reference and meaning.