Bernard d'Espagnat, 410–411
- Bernard d'Espagnat's <a href="http://www.amazon.com/On-Physics-Philosophy-Bernard-dEspagnat/dp/0691119643">On Physics and Philosophy</a>, which clears things up quite a lot. Here it is:
- <blockquote> Next, let us keep in mind that empirical reality does exhibit all the features that our everyday intuition imparts to the notion of reality. As already noted in chapter 1, a most important one—one that crucially distinguishes empirical reality from pure observational predictability—is counterfactuality. Now, we noted in section 8-2-2 that the empirical macroscopic reality notion resulting, in quantum physics, from the study of the behavior of the so-called "collective variables" is in no way at variance with the said counterfactuality. Another one of the features in question has to do with the, tightly linked, ideas of "explanation" and "causes." <b>As we noted, one of the reasons that make us intuitively prefer realism to mere observational predictability is that realism does give us the impression of an understandable causal link between events, which mere observational predictive laws fail to yield. However, in section 14-2 we noted that philosophical analyses of the said causal link notion have long since shown it to be intimately associated in our mind with the one of will, which means that at the level of our intuition it shows marked anthropomorphic aspects.</b> And what, along the same lines, is perhaps even more significant is the outcome of the analysis carried out in section 15-4. For it shows that within empirical reality there is indeed room for the notion of a definite concatenation of causes and effects (conceived of, of course, as phenomena). More precisely it shows that such a concatenation ending in an observation act should normally be apprehended by the subject (or collectivity) who makes the observation. So that the notion at hand may be kept, even within the framework of generalized measurements such as those considered in chapter 4. In other words, the analysis in question showed that even in a situation resulting from a Schrödinger-cat-like interaction, concatenations of the type "the pointer acts on a relay that acts on a flasher that acts, etc." may be considered to be genuinely causal ones. Such an interpretation admittedly is relative to us but (as already noted) <i>no more so than the very notion "events."</i>
- Finally then, should we call "mere appearances" appearances—causal ones included—<b>that are the same for all those who are able to perceive them</b> (including, perhaps, animals)? As we know, idealists answer this question negatively, and on this particular point it seems difficult to call them wrong. In fact our judgment on this matter depends very much on the meaning we impart to words. It goes without saying that referring to things conceived as being independent of us greatly facilitates everyday life. From this it follows that we have a natural tendency toward reifying. Concerning objects, this is an approach that, with regard to practical points, is entirely legitimate. It may quite well be accepted also in philosophy, but only provided we keep in mind that, by making use of this objectivist language, we, in fact, merely refer to our communicable experience. With this reservation, empirical reality, the reality that is ours, within which we are born, life, and die, does really qualify for being called "reality." In the sense just defined it would not only be incorrect but also inconsistent to claim it is merely an "appearance." But at the same time we must remember that in view of contemporary physics such a reifying proves unwarranted when we, naively, take it strictly literally. To repeat, we have to keep in mind the fact that it finally is but a means of stating in a convenient manner some possible observational predictions (and therefore of predicting and planning possible actions). And finally, within the framework of such a conception, while the distinction between (empirical) reality and "appearances in a trivial sense" of course remains essential, the one between (empirical) reality and "appearances that are the same, at all times, for everybody" clearly ceases to be valid.
- In short, we have explained and justified the use of the word "reality" for designating empirical reality. Since, on the other hand, in view of the reasons described and commented on in foregoing chapters (particularly chapters 5 and 10) we have to keep the mind-independent reality concept, we cannot, to repeat, do otherwise than take up the idea of two "orders," or "levels," of reality. (410–411)
-  Note that here the word "level" is slightly misleading since, as we already pointed out, we are not dealing with mutually comparable entities such as geological strata, for example. The word may be kept only if we give up the idea of a similarity of any kind. If we were bent on stressing how different the notions of empirical reality and mind-independent reality actually are we might do so by calling the second one "the super-real."</blockquote>