Yesterday I described how we could capture change using a variation of predicate logic. There I distinguished two ways of talking about change, either by describing how the same physical stuff happens to have different properties at different times, or by describing how the thing (or things) that fall under a particular description have different properties at different times. When discussing them in this way their similarities are obvious, the first is exactly like the second except that in the case of the first the unifying description (that which holds at both times) is “made of some particular material”. I would argue that all cases are in fact best thought of as the second type, and that the “made of some particular material” property is as much a matter of the way we perceive things (in our ordinary conception of the world) as is any other. This distinction may seem trivial, and indeed it is in many circumstances. However, I would argue that the failure to understand it is one of the things that leads people to confuse the meaning of “my teapot” with what is meant (referred to) with that same description.
Consider the case of the teapot that is turned into a pot. To describe this case in terms of my second formalization of change we would have to assert that the stuff that was “the material that composed my teapot” was at one time my teapot, and at another time a pot. However, this has not removed our appeal to the stuff that the teapot is made of, and its continuity. Thus we might argue that since the pot is, at least in part, still our teapot (in virtue of the fact that our teapot has changed into the pot, and not been obliterated and replaced by the pot). And so what we mean by “teapot” must, at least in part, contain the stuff that the teapot is made out of. From this the confusion between the meaning of the word and the things meant by it may be given birth, and from it follows the idea that somehow the meaning, a mental activity, reaches out to the teapot itself, and thus that the mind is partly external, along with other absurdities. All because of some muddled thinking.
Let’s suppose, however, that tomorrow metal turns out not to be a stable substance. Rather the atoms of metal are constantly being interchanged with those in the environment (altering appropriately so that the atoms being exchanged can play each others roles). Obviously this is not a possibility under any reasonable understanding of physics, but it is certainly possible within some possible physics. In any case, this makes the teapot more like a stream, a description that persists over time, and not a stable structure of stuff. But note that in this situation we would not necessarily be aware of this property of metal, and thus would mean the same thing by “my teapot” as we do in the normal universe. And we would still think that the teapot could change into a pot by being re-forged. Clearly then what unites the teapot and the pot is not that they are made up of the same stuff (at least not necessarily). What unites them is instead the fact they are “made of the same metal”, as we understand it. But note that “made of the same metal” turns out not to have any connection to the way the particles actually work, but rather is defined by a set of mental rules we have about when metal does and doesn’t count as the same, mental rules which treat it as basically indestructible, although divisible and re-shapeable. Since what we mean by teapot and pot is the same in both worlds, and in both we understand one as being able to be changed into the other, we must grant that even though some idea of the material is part of the meaning, as evidenced by our understanding of the change as a change, this idea is as much a product of our conception as “teapot”, and if it happens to be similar to the way the material that composes actual teapots works, well that is just a happy coincidence.
Another way to drive home the idea that the matter that actually composes the teapot is not part of the meaning is simply to illustrate that it is irrelevant to our re-identification of the teapot. For example, my teapot could be instantaneously switched with an exact duplicate and I would be completely unaware of that fact. Indeed the substituted would be to me as much “my teapot” as the old one was. Now some might argue that this is simply evidence of my ignorance. After all if my teapot was replaced with an imperfect duplicate I might still believe it to be the same item. However in the case of this duplicate someone might, at least in principle, bring me to notice the differences between it and the old teapot. At which point I would concede that it was not in fact my teapot, and that my identification had been in error. And obviously this can’t happen with the exact duplicate. And given that I would identify it as my teapot in every conceivable situation we must admit that it is in fact what I mean by “my teapot”, assuming that I am the authority on what I mean by the use of my own words.* Of course someone might argue that I am simply ignorant about the meaning of the words I use. But what makes them a better authority?
In any case, to get back to the original point, it has thus been demonstrated that the “sameness of material” that often unites objects at different times in our minds, and on the basis of which we say one has changed into another, is as much a matter of our conception of things as any other property. And so, at least on these grounds, it is clear we have no reason to conclude that the meaning contains, in any way, what is meant. And thus that the two should be kept distinct (with meaning in the mind and what is meant in the world, determining truth).
* Of course if I could be convinced that it had been switched in such a way then I would probably change my opinion, but that is because my conception of my teapot’s material doesn’t include sudden replacement. Thus we are considering everything short of this revelation, meaning we are considering whether I will re-identify it as my teapot on the basis of its current properties, which, if done without error, should be the definitive measure of whether it is or isn’t my teapot.