This post doesn’t contain any significantly new material, it is simply a collection and refinement of a series of earlier posts (specifically this one, this one, this one, this one, this one, this one, and that one).
Here I will attempt to demonstrate that externalism is a bad way of describing the mind through an objection by cases (although I like to think of it as a choose your own refutation). There are several kinds of claims that I am not attempting to refute, which some people may confuse with externalism. First I am not attempting to show that nothing depends on the external world. The belief that the truth of statements depends on the eternal world seems perfectly rational to me, and has nothing to do with the mind (see here). Secondly I am not trying to argue against the idea that we need the external world in order to understand the mind, because this claim is trivially true about everything, and thus says nothing interesting about the mind. (For example a vase cannot be understood in the absence of the rest of the world, because the idea of what a vase is requires some sense of its purpose, the existence of flowers, ect.) Finally I am not trying to show that the mind cannot grasp a priori truths (specifically tautologies), or that there are no such truths, because I have argued earlier that such truths are not properly part of the external world in the first place (see here).
2: First Step
Let me begin by dividing the possible interpretations of externalism into two groups. Either the relation between the mind and the external world is a causal connection, in which case proceed to section 3 for a refutation, or the connection is non-causal, in which case proceed to section 4.
3: Causal Views
There are two significant problems with an interpretation of externalism that attempts to define the connection between the mind and the world as casual.
3.1: The Problem of Fictional Objects
Lets say that our view of externalism is that the connection to the external world is somehow providing content for our thoughts (or the sense/meaning of them). If this is the case how should we account for fictional entities? A fictional entity, let’s say Darth Vader, can’t be the cause of any of our mental states, because he doesn’t exist. It is true that our mental states are causally affected by stories about Darth Vader, but we have the ability to think of Darth Vader himself, not just about certain movies that he was in. Since it is impossible to reasonably deny that people can direct their thoughts at such non-existent entities we should be inclined to discard an interpretation of externalism that dictates that a causal relation between the world and the mind provides meaning or content for thoughts.
3.2: The Reduction to Internalism
Of course perhaps the external relation doesn’t have anything to do with conscious thought, and thus we feel it might escape the objection presented above. Let us consider then a causal version of externalism as a real possibility. We would say then that the mind is connected to an object, say X, by X’s causal influence on the mind. Let’s examine then what this connection means at a given instant of time. Certainly when we look back to the moment of time where whatever information about X that influenced that mind was generated it might seem reasonable to say that our future thought about X is dependant on that X in the past and the mind in the past. However as we consider moments in time closer to the actual thought X falls out of the picture, and instead what we consider to be connected to us is the medium by which the information about X was transmitted (say the reflected light). When we reach the moment of the actual thought there is nothing left from X that we can consider to have a causal effect on us, because the effect of X on us happened some time in the past. When considering that moment of time, the moment when the thought happens, all we can say is that we have a thought about X, even though the thought isn’t connected to X. For all intents and purposes this is the same as internalism.
4: Non-Causal Views
The non-causal view of externalism can be further divided into two views. One interpretation of externalism holds that the connection between the mind and the external world has real (and hence observable effects) on behavior, consciousness, or the unconscious. Proceed to section 5 for a refutation of this view. On the other hand we can interpret externalism as primarily definitional, and hence we should expect that the connection between the external world and the mind has no observable effects. Proceed to section 6 for a refutation of this interpretation.
5: Real Effects Views
If the connection between the world and the mind has real and observable effects then we should be able to detect this connection through experiments. Below are two experiments (which you can do on your own) that demonstrate that the external world does not have a non-causal connection to behavior, consciousness, or the unconscious.
5.1 Effects on Behavior / Consciousness Experiment
A non-casual theory of externalism could hold that our consciousness or behavior about an object, about say a soap bubble, participate in a relation between us and the soap bubble, and that this relation has a real effect on either our consciousness or our behavior. So then blow a soap bubble and, before it disappears, place it behind a curtain, wait a few seconds, and then take it out. Sometimes it will have popped while it is behind the curtain and sometimes it will have remained intact. However no matter what actually happened your thoughts about the bubble, and your behavior, including language behavior, weren’t affected (assuming you weren’t in direct contact with it). Your interactions with other people about the soap bubble, and your subjective awareness of your thoughts, are the same when the soap bubble stays intact and when it pops, given that you can’t see it (or at least that was the result of the experiment when I preformed it). Thus there is no way to tell the difference between your thoughts in the case of the intact bubble and the case of the popped bubble. This is exactly the opposite of what this interpretation of externalism predicted, and hence we should reject it.
5.2 Effects on the Unconsciousness Experiment
It is possible of course that the real effects of the connection claimed by externalism are on the unconscious mind. In which case we can run another experiment designed to reveal if there are any unconscious impulses that are attuned to the existence of the bubble. We do this by asking the subject to guess whether the bubble has popped or not. If they guess correctly we give them a piece of chocolate, and if they guess wrong we smack them with something blunt (make sure your volunteers are willing). If the person never achieves better than 50% accuracy this is pretty good evidence they aren’t sensitive, even unconsciously, to the existence of the bubble. (Such experiments have a well-known history of revealing unconscious knowledge/sensitivity.) Although you can run this experiment for yourself (and I have), you can also take a look at professional studies of “esp”, some of which are set up in a similar manner (for example the subject may be asked to determine which card from a set the experimenter is holding, if the subject has a connection to the cards they should be able to tell unconsciously even if they have no psychic powers). Performing this experiment, or looking up the results of previous research (but remember to find studies from neutral parties, don’t expect the esp foundation to conduct unbiased experiments) reveals that if there is an unconscious awareness of the bubble it is small enough to be hidden by experimental error.
5.3 A Possible Objection
A possible response is to defend the externalist connection as not connected to specific thoughts but the content of “classes” of thoughts. Under this interpretation it is not a specific thought about the bubble that is influenced by the externalist relation, but the content of a class of thoughts that is the “template” from which all my specific thoughts about the bubble are derived. This interpretation would still fall into the same problems facing the standard theory, so we make the additional assumption that this class is “timeless”, specifically that it is related to the bubble when the bubble existed, but because the class itself is timeless it can provide us with the content for our thoughts even when the bubble is gone. Of course this is basically the same as reintroducing the theory of forms in another guise, and thus I would reject it for the same reasons that we doubt the existence of the forms. Of course as I have argued before something that is always present can’t be considered a real cause (see here), or at least not one that we can know about, and hence the objections in section 6 should apply.
6: The Definitional Interpretation
So finally we arrive at a point where the kind of externalism we are considered is purely definitional. It doesn’t have observable consequences, nor is the external relation causal. In this case the following three objections are relevant
6.1 The Problem Of Other Minds
The problem of other minds is a classic part of philosophy. The question is as follows: how can I be sure that other people are conscious in the same way I am? (And also how can I be sure that things such as rocks aren’t?) I think that any theory about the mind that can’t solve the problem of other minds is lacking something important, and should be rejected, since it certainly seems as if we can be sure who has a mind and who doesn’t. For example dualism and idealism are famously unable to satisfactorily solve the problem of other minds, which I personally think is a good reason to discard them. Externalism can’t solve the problem of other minds either (and internalism can). This follows from the following argument: The only things we can observe about other people are physical or that which can have a causal effect on the world. We can observe their behavior directly and we can make guesses about the activity inside their skull, but that is about it. Externalism asserts that there is a non-causal connection between thoughts (part of the mind) and the external world. It is a consequence of externalism that for a mind to be a mind (and have thoughts) it must possess this non-casual connection. Why? Well if it wasn’t required then such a connection wouldn’t be an essential part of the mind, and thus we wouldn’t consider externalism to be a good theory about the mind. (For example even though the statement that “some minds believe externalism” is true it isn’t a good theory about minds because it doesn’t tell us anything about what is essential to minds in general.) However we can never be sure when such non-causal connections are present (since as mentioned above we assumed that externalism didn’t have observable consequences), and thus we can never know with any degree of certainty if other people have minds like ours, since we have no evidence either for or against their possessing the necessary non-causal external connections.
Some might object to this argument, stating that language contains a non-physical connection to the external world, and thus language use gives us reason to believe that the mind has a non-physical connection. However from the following argument we can conclude that language either doesn’t have a non-physical connection, or doesn’t provide evidence of minds, and thus that this response doesn’t solve the problem of other minds for externalism. Consider then the following situation: you shake a box of blocks and spill them on the floor. To your surprise they spell: “stop shaking me”. If you believe that these words contain a non-physical connection to the world then clearly this connection isn’t a reason to believe that something has a mind, since the box doesn’t have a mind. On the other hand if these words don’t contain a non-physical connection then there is no reason to believe that any words you come across have such a connection, since there is no difference between the words spelled out by the blocks and words created by people, at least as far as you can tell (and a simple experiment could prove this).
6.2 The Problem Of Theory Strength
Given the kind of externalism we are discussing here, the best we can say about externalism is that it is true in the sense that it is consistent. Internalism however does make claims about the contents of the world, as well as make testable predictions, and thus the truth of internalism is a matter of certainty (not that I am saying that we are currently certain about internalism, just that we could be, given the categories of knowledge discussed in the linked post). For example internalism predicts that activity in the brain will be closely correlated with what people are thinking about, and indeed experiments have shown this to be true (or at least highly probable, since you can never eliminate all experimental error). Internalism is also incompatible with externalism, and given this we should accept internalism, and reject externalism, because of the general principle that we should accept truths that could be certain over those that are only consistent. Why should certain truths trump consistent truths? Well consider the following situation: the theory that everything is made up of the four elements can be considered a consistent truth, if we are allowed to define the four elements as we please (for example air might be subatomic particles a, b, c; earth might be … ect). However the atomic theory (everything is made of atoms) is part of the realm of certain truth, since it makes definite predictions about what we will find, its truth isn’t guaranteed by definition, it must be confirmed by experiment. We settle such cases using the principle I invoked earlier, not because it is necessarily wrong to accept the elemental theory given the right definitions, but because we seek greater predictive power and hence the atomic theory is more useful to us in our search for the truth. I argue that the internalism / externalism divide is much like this. Externalism doesn’t explain anything that internalism doesn’t, it is simply a more convenient way to talk about certain situations. Internalism on the other hand does make predictions about what we should find in our physical investigations into consciousness, and thus is of greater use in our search for the truth about the mind and consciousness.
6.3 The Epiphenomenalism Objection
Although it is logically possible for the mind to be epiphenomenal (to have no effect on actual behavior) many find that conclusion to be unacceptable and to warrant discarding any theory that would lead to it. If the mind as described by externalism really isn’t epiphenomenal then it must be a cause of behavior, and so if we work backwards from behavior we should encounter something that can be considered the externalist mind (however an externalist chooses to define it). Immediately of course behavior is caused by the activity of neurons, which in turn are caused by the activity of other neurons. No matter how far back we follow these causes we never have evidence of a non-causal connection, only purely causal connections between neurons and other neurons, and neurons and sensory inputs. This in turn implies that either the non-causal connections that are part of externalism are not part of the mind, which really is the cause of behavior (and this is effectively a denial of externalism), or that the non-causal connections are part of the mind, but that this mind isn’t a cause of behavior (epiphenomenalism). Both these conclusions seem to imply that externalism should be dropped in favor of some other theory.
I should mention that there is also a “split-mind” possibility, namely that some of the mind is responsible for behavior, and is found by our investigation into behavior’s causes, and that there is another part of the mind that the non-causal connections are part of, but that it is not connected to the part of the mind that controls behavior. I reject this possibility because it still leads to the conclusion that the mind is at least partly epiphenomenal, and more strangely that it is composed of two completely separate parts that don’t affect each other (this is not the same as the right-left hemisphere division because the two hemispheres do communicate, through both the corpus callosum and the hindbrain).
7: Concluding Remarks
From the above arguments I am satisfied that externalism is a bad way of thinking about the mind. I know there are some who will say that the way I understand the mind is not the same way externalists define it. Of course anyone is free to re-define words as they wish, but the way I have used the idea of mind here is consistent both with the way ordinary people speak about the mind, and with the way it is understood in the philosophy of mind. So if externalism isn’t making claims about the mind in either of these senses I guess I have no idea what it could possibly be describing.