On a paradox in quantum mechanics

Abstract

According to the natural philosophy of Empedocles it is a fundamental law of nature that things which are members of a common species of one of the four basic elements, e.g., two batches of water, tend to attract each other, i.e., they have a "natural affinity" for each other. There are many reasons why modern science rejects this sort of view, but there is one objectionable aspect of the Empedoclean view which makes it particularly suitable for my discussion. This is the idea that the species of things as such can be a fundamental factor in causing, and thus in explaining, the behavior of things. This idea is exemplified in the claim that the mere fact that a system consists of things of the same species causes the system to behave in ways it would not otherwise. Today we would say that an account of electricity which took as a fundamental principle "electrons repel each other (because they are of the same species)" is just as unacceptable a candidate for a fundamental account of the nature of things as Empedocles'. The standard explana tion of this electrical phenomenon, viz., any particles of like charge re pel each other by virtue of the interaction of these particles with the electromagnetic field, provides an account in terms of fundamental properties and mechanisms or processes, in which no irreducible reference to the fact that the particles are of the same species is made. Why are such "natural affinities" out of place in physics? We are aware of cases in which things exhibit definite modes of behavior when they are together with things of the same species, e.g., the social behavior of animals of the same species. While we may not know the mechanisms which make such behavior possible, we know that there are genetic, physiological, environmental, social, etc., structures in volved, and we believe explanations of such behavior by means of these structures is always, in principle, possible. We would not be apt to say that it is simply a fundamental fact, unexplainable in terms of anything