Seeing red

[Angrboda]

Opinion 2…ideas are things just as much as a desk or a glass is a physical thing…The evidence from science and medicine is that the mind behaves consistent with it being an object like any other.

Opinion 2 apparently considers ideas to be identical with certain types of sensible bodies and/or their behaviors. It ignores the fact that sensible bodies, like physical desks or glasses, aren’t about anything in the way that thoughts and feelings refer to things beyond themselves.

Speaking of arguments from ignorance, this is nothing but one. Since you can't imagine how things or systems of things can be about other things, you simply declare it cannot be so. There are at least two kinds of aboutness to which this might refer. The first is the aboutness of words in a language game. The bulk of the mental processing in language occurs below the level of consciousness, so claiming you have full lucidity on how words refer would be sheer excess. We may have evolved language millions of years ago, so untangling its behavior and operation may take some time. The other type of aboutness is what philosophers refer to as intentionality. For this, a simple counter-example will suffice. Every year there is a race held in the desert to compare completely robotic vehicles' performance on a pre-determined course. These vehicles use a variety of sensors to track the terrain as they drive along. They 'map' the road as they come upon it. To suggest that the data in these onboard computers is not 'about' the road in front of them is ridiculous. This is a clear example of a system having a form of intentionality; the data in these robots is about the road conditions just as surely as my visual perception is about the computer in front of me.