One type of objection to the explanatory stopgap is that which questions the idea of inner perception. Many of these deal more closely with cognitive science than I am able to do with my own limited knowledge of the subject. A more basic type of objection questions the steps of the stopgap argument itself. Perhaps the most promising target of such an objection is the transition from “c’s having M is like something for c” to “For some F, c’s having M is F-like for c”. Someone putting forth this argument would probably say that, despite what the O.E.D. may have to say about the words “something” and “like”, the sense of the phrase has changed drastically between the two steps. He or she would probably say that, in this case, saying an experience M is “like something” does not imply the existence of some particular predicate F, to which having M appears similar.

However, it seems that the only way such an objection could really stand is if people making it admit that they don’t really know what they mean when they say there’s “something it’s like” to have an experience. If they did know what they meant, they should be able to explain it accurately using common English words, instead of denying the applicability of the definitions of the words they use when describing experience. But would admitting ignorance in this regard have any major impact on the objection itself? It is likely that the people who would bring up the objection are those who maintain that there is something “mysterious” about conscious experience that prevents it from being fully explained in terms of physical processes. Perhaps the mystery of consciousness includes rigorous verbal explanations, in addition to purely physical explanations. If this is the case, then a person might have a valid complaint in saying that words are being used differently in different steps of the stopgap argument.

Of course, if a person admits ignorance, then the objection appears to presuppose that there is something mysterious about conscious experience, in which case it’s not a valid objection. But if a person is unwilling to admit complete ignorance, the objection can still carry some weight. There are many examples of perfectly acceptable uses of words whose meanings we all know, which lead to absurd conclusions when rigorous logic is applied to them. To take one of the most well known examples, let us analyze the word “heap”. If we look at how the word is commonly used (that is, if we look at its definition), we will find two basic characteristics of the concept of “heap”. First, if it takes n grains of sand to “form an elevated mass…roughly conical in form”, then n grains of sand constitute a heap. Second, we can assume that if k grains of sand constitute a heap, adding or removing a single grain will not affect the “heapness” of the remaining collection. Now, if we apply basic inductive logic to these two statements, we have that any number of grains of sand constitutes a heap of sand. Thus we have reached an obviously false conclusion, despite the fact that we all know what is meant by the word “heap”.

This is but one of many examples of concepts whose meanings we understand but can explain only vaguely. It almost seems as if the concepts are too “fragile” to be treated very rigorously, and that by doing so, we inadvertently destroy their meanings altogether. In general, though, the words “like” and “something” can be treated far more rigorously than “heap” without losing any of their important meanings. In fact, if we weren’t talking about consciousness, the move from “c’s having M is like something for c” to “For some F, c’s having M is F-like for c” would probably be perfectly acceptable to most anyone. So maybe the problem is still due to nothing more than the presupposition of something mysterious about consciousness. On the other hand, it’s possible that the necessarily vague concept in this situation is not “like something”, but rather “something it’s like”. Perhaps the sense of that phrase, when used to describe conscious experience, is radically different from the normal senses of each of its component words. The sense of “something it’s like” used here may indeed fall into the same category as “heap”, in that it is a concept that we understand vaguely, and to which we can’t apply rigorous logic without destroying some or all of its original meaning. If that is the case, then even the moves from “there is something it is like to have M” to “c’s having M is like something for c” change the sense of the words being used, in which case the stopgap argument really doesn’t solve the problem of the apparently mysterious nature of consciousness.