I had to write about this topic in one of my final exams, but here is the extended version.
The question is about externalism of mental content. Everyone agrees that some of your thoughts are conditioned by your surroundings (my belief that it is sunny in Boston right now is conditioned by the fact that I feel warm in my shorts and polo in Boston at this point. Were it not for what is going on outside (i.e. the fact that it is actually quite warm) I would not be experiencing that feeling. However, the question externalists pose is whether there are any thoughts which are entirely personal and which do not have to do with the society around some person. This would be easy to respond to, but the added complication is “mental language,” i.e. that we use language in our inner thinking, so it seems very likely that since society affects language, it should also affect everything we can think of. I will review the two classic arguments for externalism and then move on to create a positive argument for internalism.
The first classic argument was put forth by Putnam in 1975 and it treats the case of Oscar and Toscar. The scenario says that it takes place before 1750 (i.e. before it was discovered that water was H2O). There is Oscar, who lives on Earth and his twin (i.e. a perfect replica of him) in close possible world, Twin-Earth, which is the same as our planet, except for the fact that instead of H2O, the substance they call water has the chemical formula XYZ (and they too don’t know it). Putnam’s argument is that when Oscar says, “Water is quenching,” he means H2O is quenching, when Toscar says it, he means XYZ is quenching. In addition, it is correct to call the liquid here on Earth “water,” but it is not correct to call XYZ water. His scenario goes on.
There are several problems to this thought-experiment. First of all, even though Oscar is correct when he says “water” and Toscar is not, even though there is a change in the truth value in between those two statements, they are not arrived as a conclusion of logical premises (at leas the naming of the liquid is not), but as a guess (since neither twin knows that water is H2O). Even in our own planet, the same (or a very similar) succession of sounds means two very different things among different groups. Is it logical then to say that whenever Group A uses that word they are right, but whenever Group B uses it they are wrong?
Second, there is the problem of changing the environment without changing anything in Oscar’s twin (he needs to be a perfect twin for the thought-experiment to work). Well, Oscar’s body (as all of ours) is made out of about 60% H2O. If Toscar is the only person in Twin-Earth who has H2O in his body instead of XYZ, then the scenario changes, because there is both H2O and XYZ in Twin-Earth and, supposing that the Twin-Earth people have good irrigation, some of Toscar’s pee and sweat (after being purified) have found their way into the “waters” of Twin-Earth, which have made a mixture between XYZ and H2O.
Third, the question is raised about whether it is logically consistent to think of XYZ. For the experiment to work, XYZ needs to have all the same properties as water, except for one, it is XYZ instead of H2O. The problem arises, however, when you consider the fact that it is its being H2O that gives water all the other properties. It seems, therefore, that XYZ would have to be a variation of water. Leibniz’ Law of Indiscernibles then comes into play, since two things which have all their properties in common cannot be numerically distinct. That is to say that XYZ cannot be considered something different from water and, therefore, it is not wrong to call it water.
The second argument seems to me to be even weaker that the first. It is put forth by Burge in 1979 and 1986 and it seeks to show that Jane and her twin (perfect replica) are right and wrong in their environment. The thought experiment poses that Jane, an English-speaking female, has a pain in her thigh. For some reason, she is convinced that arthritis describes pain in the joints and in the thighs. Burge then asserts that when she says, “I have arthritis,” she is uttering a wrong sentence. However, when Jane’s twin, who lives in the close possible world where arthritis does cover thigh pain, is right. Now let us see the problems with with argument.
From the very beginning, this argument misunderstand what it has to prove. When Jane “says” a sentence, she could be wrong, the question here is about thought, but that is a small and semantic point, which has room to be considered as a counter-argument, but perhaps you don’t agree.
In addition, this thought-experiment forces us to think about what words are. Do words have intrinsic meaning, or do they derive their meaning based on their definition? If you hold to be part of the first group (Cratylus talks about it), just follow me here, what I mean is a little different. Consider this scenario. Say one objectively true fact about quompth. If you say quompth is beautiful, I’ll reply that that is relative, if you disagree with that, the statement is still about the string of sounds or letter that make up that word and we cannot consider any string of letters or sounds to be defined as a word, otherwise things would get quite confusing (aslidhslkah would be a word under that definition). If I were to ask you to give me an objectively true fact about “sphere,” you’d not really have that much trouble with it. Here’s one, “a sphere is always circular.” Let’s try another example. Consider qerpik. This one is so weird that I bet you can’t even pronounce it right. State one objectively true fact about qerpik. If you are reading this and you have an objectively true fact, then please put it in the comments, because I am at a loss.
What do these examples show us? Take any string of sounds (in a basic sense, that’s what a word is) and strip it of its meaning (that’s the second condition, in my mind) and there is no way for you to use it in your thinking. Now, you could assign your own internal meaning to it and use it for your thinking and that’s perfectly valid. For example, when someone looks at my notes, they are initially very confused, because I use a system of symbols for some words. Again, that’s perfectly valid in my case, but if you are looking at them for the first time (and can’t guess when judging from context), you’d think it was just a collection of words and symbols which don’t correlate. That means that though we speak in words, it is really their definitions that we are thinking, so when twin-Jane says “I have arthritis,” her mental content is that she has a pain in her thigh and she chooses to communicate that pain by associating it with arthritis. I don’t think that there is anyone who’d argue that when the Englishman says about a rose, “It is red,” that his mental content is different from the Frenchman, looking at the same rose who says, “Il est rouge,” they are just communicating the same concept with different words. On these grounds, it seems to me that there is a very good chance that externalism about mental content is false.