In the article from The Oxford Handbook of Philosophy of Mind that I mentioned in my last post, Howard Robinson goes on to provide an explicitly formulated argument for idealism. The argument goes as follows (p. 200-201):

  1. Our conception of the world, as shown in our language about it, possesses logico-grammatical complexity, and certain features of this complexity cannot be treated straightforwardly as representations of aspects of concrete, mind-independent reality.
  2. Therefore, if there is a realist conception of the world, it must be possible to separate those features of our conception of the world which can be treated in a straightforwardly realist way and those that cannot. It is the former that constitute the realist conception of the world, and the states of affairs they represent must be enough to constitute the realist’s world.
  3. It is not possible to make the distinction specified in 2.
  4. Therefore, a realist conception of the world is not possible.

Robinson’s evidence for premise 1 is that states of affairs allegedly do not seem like the kinds of things that could exist in the concrete. An electron is concrete, but how could its having such and such a charge or such and such a mass exist in the concrete? Robinson is especially puzzled by negative states of affairs like “there is no pen on this table.” It is unclear to him how an absence could exist in the concrete.

I’m not really sure how to respond to this argument. At first, I would be inclined to say that just because we don’t know how to explain something doesn’t mean we should leap to an exotic explanation like idealism. That’s similar to what fundamentalists do whenever they find something that science can’t currently explain – insert God as an explanation. But I doubt that Robinson would find this response convincing.