5 THE ONTOLOGICAL CONTENT OF QUANTUM MECHANICS
At the end of Chapter 3 we described the import of the EPR paper as an invitation to choose between two positions. The first position was explicitly taken by Einstein in order to question early attempts at creating a theory of the constituents of matter and was so perceived by the creators of that theory. He argued that, if constituents of matter were, as he firmly believed, objects of experience, one ought to be able to ascertain all their properties through ordinary measurements conducted on them and any theory which, like quantum mechanics, holds otherwise must be incomplete. Because it questions the degree of knowledge provided by the theory, we call this position epistemological.
The second position asserted that if quantum theory was, as the creators firmly believed, a complete representation of how the constituents of matter behaved, those constituents could not be objects of experience. This argument was not explicitly made by Einstein but was only contemplated by him in rejection. In his autobiographical notes, Einstein says:
On one assumption we should, in my opinion, insist without qualification: the real state of the system is independent of any manipulation of the system which is spatially separated from the former.
By thus emphatically rejecting any dependence between the states of two spatially separated physical systems, Einstein pre-asserts the possibility of such a dependence. But, this assertion of a possible dependence between the states of spatially separated physical systems is really an ontological assertion. Indeed, because at that distance there can be no question of any physical interaction being exerted between them, the only reason why the states of the two systems might not be independent of each other must be that the systems under consideration are not anything like the objects with which we are experientially familiar. It does not matter whether one wished to explain that dependence “by assuming that the measurement performed on one system telepathically changes the real state of the other system or by denying altogether that spatially separated entities possess independent real states”, constituents of matter would then simply not be objects of experience; the reason for the dependence must, in other words, be ontological. We consequently call the position taken in the quotation above, the ontological position.
We thus wish to interpret Einstein’s paper as a declaration that physicists were then standing on the threshold of a turn in the development of their theory and that the direction in which they chose to turn depended upon the stand they would take concerning the manner of being of the objects described by that theory. If the manner of being of those objects was taken to be that of an object of experience, physicists would have to modify their theory until it became a complete accounting of all the properties characteristic of such objects. If, on the other hand, their manner of being was taken to be different from that of an object of experience, physicists would have to understand how that manner of being was related to the act of observing them. In the event, physicists took the stand that constituents of matter were probably not objects of experience but failed to seriously pursue the question concerning their ontology. The younger generation viewed the issues raised in the EPR paper, to the extent that they paid much attention to it at all, as a matter of experimentally verifying quantum entanglement and lost interest in them altogether after Alain Aspect succeeded in experimentally verifying that the linear polarization of the two photons emitted in the radiative atomic cascade of calcium remained forever thereafter correlated with each other. The fact that Einstein’s objection was not really concerned with the existence of this correlation but rather with the ontological implications of that correlation, went unnoticed.
In this chapter we intend to accomplish two things: show how the creators of quantum mechanics came to thus skip over the ontology of the objects they were studying and show how, having thus ignored the ontological difference, the resulting theory was bound to exhibit the strange features which characterized quantum mechanics.