November 29, 2012
My friend and colleague at Biola, Scott Smith, has written a new tour de force book, entitled, Naturalism and Our Knowledge of Reality. Smith's book is so thorough and sophisticated to do justice to it here, but I want to supplement one argument he makes in the book to the effect that if we accept materialistic naturalism, them semantic meanings will have to be reduced to syntax and this reduction fails.
The reduction Smith has in mind proceeds in two steps:
(1) Identify semantic meanings with indicator meaning;
(2) reduce thought to the brain's computational functioning on a brain language of Mentalese.
I want to say a word about step (1). Some physical stage P contains indicator meaning M just in case (i) M caused P and (ii) P was designed or evolutionarily selected precisely to register M. Thus, the state of a thermometer "means" the temperature; a brain state caused by a cows "means" that a cow is present given that such a state was selected by evolution to indicate the presence of a cow. Now there are many problems with this reduction (e.g., it turns out that cow piles "mean" cows, and it's hard to thing of cow piles as having semantic properties!), but I want to mention one here. Genuine semantic contents, e.g., that snow is white, have the properties of being true or being false.
Now consider the face of the Grand Canyon. It does have information/indicator meaning in the slim sense above in that it registers the effects of erosion, fish fossilization, and so forth. Thus, in a sense we can say that a certain section of the face "means" that erosion occurred during such and such time. But it makes no sense to saw that the face of the Grand Canyon is true. Contrast this with a picture of the Grand Canyon places in the wall of a geology class by the instructor with labels indicating various areas of the face. These labels or map locations could be true or false because they were put there intentionally to mean certain things to the students. If semantic meanings have truth values and "information" or "indicator meaning" does not, then the latter is not a legitimate candidate for the reduction of the former. And that point supplements Smith's arguments in his wonderful book about the impossibility of knowledge, given a widely accepted form of naturalism.
In addition to issues about semantics and syntax, there is a further one about the nature of intentionality relevant to professor Smith's book. He argues, correctly in my view, that intentionality is a primitive monadic property of ofness/aboutness that cannot be reduced to anything physical. Now if this is true and given that intentionality is a mental property, if it is indeed basic in the universe, it would be fairly easy to develop an argument that there is a fundamental Thinker whose various mental states exemplify intentionality. Most naturalists (John Searle is a notable exception) reduce intentionality to a causal relation, e.g. to have a sensation of a rose is for the brain to stand in an appropriate causal relation to the rose.
But I think it is possible to show that standing in such a causal relation is neither necessary nor sufficient for having a sensation of a rose. First, it's not necessary: If God decided to suspend causality for, say, a day, and run the world in an occasionalist way such that He directly caused all events in the world and there were no causal chains between "natural" phenomena, then if one had the relevant sensation of "being appeared to rosely", it would still be of a rose even if it wasn't caused by the rose. Second, it's not sufficient. Suppose that every time Jones looks at a rose he stands in a regular lawlike causal relation with it such that he is caused to have a sensation of an elephant. Surely, there is a possible world where this takes place. If so, then standing in the appropriate causal relation would not be sufficient for having the relevant rose sensation. For these and other reasons (e.g., I can tell what my sensation is of by just directing my attention to it in total disregard of any causal relation I sustain to the relevant object), I believe Dr. Smith is correct in saying that intentionality is basic and irreducible.
Scott Smith's overall argument in Naturalism and Our Knowledge of Reality is a force to be reckoned with. It's no wonder that Durham's E.J. Lowe said that "All self-proclaimed naturalists, as well as their opponents, would do well to reflect on its arguments."