This is just a quick response to an objection to my earlier post on intentionality I found here. The objection can be summarized as follows: that in my “thought experiment” I have already assumed the conclusion that thoughts are localized in the brain. I argue that this objection is invalid because I am not discussing a thought experiment at all but a real experiment that I actually carried out in order to test the nature of intentionality, I didn’t assume a conclusion, I discovered it by experiment.
Perhaps though the best way to defend my conclusions is to explain the logic behind them more thoroughly. My reasoning was as follows: if we assume that externalism (or non-causal intentionality) is correct it some follow that the contents of our thoughts depends (non-causally) on the contents of the world. From that statement it follows that either the subjective experience of our thoughts, or our actions (specifically speech), depend on the contents of the world, since these are the only possible ways that we can make sense of the idea of “contents of thoughts” or simply have access to those contents in our lives. Thus when we run the experiment with the bubble we expect that if externalism is true there will be some difference in the contents of our thoughts when the bubble remains intact and when it pops, even if we aren’t observing the bubble (since the connection is non-causal). Since the contents of my thoughts was independent of the existence of the unobserved bubble, as far as either I or my partner could tell, either subjectively or based on how I was able to express myself about the bubble, we must conclude that one of the assumptions that lead us to this conclusion was false.
One possible defense for the externalist is to argue that the content of our thoughts doesn’t influence either the experience of thinking or the public expression of our thoughts. If this is the case it seems that the content of our thoughts doesn’t have any real influence on our thinking at all, and thus seems silly to say that it is somehow part of our minds. I could understand a position where the contents of the world were seen to have a (non-causal) impact on the objective truth of our thoughts, but the objective truth of our thoughts isn’t a factor that seems to be part of our minds (it would be much harder for people to make mistakes if objective truth was part of peoples’ minds, since they would be able to tap into their “truth sense” to correct their errors).
One could also argue that the content of thoughts influences our thinking only some of the time, or only for certain people. I will reject these responses out of hand, simply because they don’t provide explanations of why or how this could be the case. Let us make them more concrete then by insisting that the intentional relation influences our thinking only when we directly perceive the objects we are thinking about. This claim however is essentially a more limited form of the causal version of intentionality, and has the same failings.
I look forward to hearing more defenses of externalism, since it seems to fly in the face of all the experimental evidence we have regarding the relation between the brain, the mind, and our subjective experience of consciousness.