When Popper talks about scientific discovery, he implies that truth is out there as yet independent of observation. ...Even taking Bruce at his word about Shermer's views (he doesn't cite any source, and his latest essay shows his... relaxed... standards about careful reading) should we conclude that scientists and skeptics are indeed committed to metaphysical objectivism? I argue that yes, scientists do believe objective reality, but no, this belief isn't metaphysical in any nontrivial sense. The notions of "reality" and "objective reality" are falsifiable, and thus scientific, not metaphysical.
I’ve (albeit casually) quizzed scientists on their belief in an objective reality independent of the observer and its importance to their work as scientists. Generally their views are similar to what I’ve attributed to Popper. ...
Heck, popular skeptics... aren’t exactly in denial of metaphysical objectivism either. Michael Shermer of the Skeptics Society (not speaking on their behalf) has opined his view of an objective metaphysical reality (as oddly un-Kantian as this may seem for a skeptic). ...
(Be forewarned: I unapologetically take some cheap shots at philosophy and philosophers in general along the way.)
It's not even clear that all scientists believe that their work has much to do at all with reality. In The Universe in a Nutshell Stephen Hawking opines:
[A] scientific theory is a mathematical model that describes and codifies the observations we make. A good theory will describe a large range of phenomena on the basis of a few simple postulates and will make definite predictions that can be tested.Of course, Hawking speaks only for himself, but he's famous enough that we can conclude his views are shared by a nontrivial number of other scientists.
Conspicuous by its absence in the above quotation is any mention of reality. To the extent we can draw conclusions about Hawking's philosophical view on reality, we must conclude that scientific work has nothing at all to do with this metaphysical objective reality: science describes and codifies observations, not "objective reality".
(I suspect, however, that Hawking is being politely disingenuous here. I myself am not quite so polite: I'll say right out loud that I read this statement as a big "fuck you" to
I suspect that — Hawking notwithstanding — most scientists believe at some level in an objective reality, with existence and properties independent of the human mind, and that this objective reality can be accurately described by scientific means.
We can assume arguendo that scientists are typically unreflective about their belief in objective reality. (To the extent that they are reflective, at least publicly, one can examine their arguments directly and not appeal to mere facts of belief.) Scientists are not philosophers. The existence of objective reality seems (outside philosophical circles) uncontroversial; no scientist is going to get grant money to publish a peer-reviewed paper establishing that yes, reality does in fact exist.
Unfortunately, the word "metaphysical" and its derivatives have been deeply abused by the philosophical canon, bludgeoned — if one is not selective about its interpretation — into meaninglessness. In one sense, "metaphysical" is a synonym for "ontological" (pertaining to existence); in this sense, of course, any belief about existence and reality is metaphysical by definition. But that doesn't seem a particularly interesting definition in the current context. Other definitions are all over the place. If we're committed to taking into account everything every philosopher has ever said or implied was "metaphysical" in print, we're doomed to a hopeless morass of confusion and ambiguity.
(Such a morass seems to suit (at least some) professional philosophers just fine. They can bloviate endlessly about a fundamentally ambiguous topic, free of the danger that they will eventually reach an actual conclusion and thus be forced to attempt original work. Philosophy is all about the questions, dontcha know; not about the answers.)
The key word here is metaphysical. Are scientists' unreflective beliefs in reality specifically metaphysical? Does the fact that a belief is held without reflection establish by itself that the belief is therefore metaphysical?
Bruce's argument that scientists typically believe objective reality without offering any specific arguments would seem — on a non-trivial substantive definition of "metaphysical" — to be an argument from non-reflection. (Bruce might claim a trivial, vacuous or at least obviously unproblematic definition of "metaphysical"; good for him, but even in the best case of an obviously unproblematic definition, his argument would thus be a restatement of the obvious.)
If we want from philosophy something more than admiration of the philosopher's bullshitting skill, we want a meatier definition of "metaphysical" than simply "unreflective": We'd like the word to actually do some real work.
One of Popper's key points — contra the Logical Positivists — is that falsifiability is explicitly a demarcation criterion, not a criterion of meaning. Good for him: otherwise the statement, "Falsifiability distinguishes between science and metaphysics," would be unfalsifiable and therefore meaningless. If some statement is falsifiable, it is scientific; if it is not falsifiable, it is metaphysical.
(Complicating the issue somewhat is that not all unfalsifiable statements are metaphysical; some — such as "asdf ghjkl qwertyuiop" — are indeed totally meaningless. Further complicating the issue is that falsifiability is ambiguous — fatally so — regarding individual statements; an individual statement cannot even in the most abstract principle — be decisively isolated from its theoretical and linguistic context. Some individual statements, however, can justly be called falsifiable on their own merits relative to some context; other statements seem to resist being seen as falsifiable without changing the context so radically as to be unintelligible.)
If, of course, we are interested only in what actual human scientists actually think, we need not go beyond asking them what they think and cataloging their responses; we might even draw some conclusions from those responses. But those conclusions will be conclusions about what scientists think, not about the world, at least not about the world outside scientists' minds. (And even this simplistic approach has its problems. Who, for example, counts as a "scientist"? Should we admit astrologers, chiropractors, intelligent design advocates? How about psychologists, anthropologists and sociologists. Should Camille Paglia* be admitted on the same basis as Bob Altemeyer**?) Again, though, if one expects more from philosophy than mere lexicography or psychology, it seems possible investigate the issue a little more deeply.
*At best a polemicist; at worst an idiot
**A terrific scientist
If we follow Popper's definition of metaphysics as "meaningful but unfalsifiable statements", then the question becomes simply: can we falsify our belief in an objective reality independent of our beliefs? If so, it's a scientific statement; if not, it's metaphysical. Much depends, however, on how we define "independent", "objective" and "reality"; in other words, the linguistic context necessary to assign meaning to the statement is not fixed, even by arbitrary linguistic convention.
If we take independence in its strongest sense as "absolutely uncorrelated" and belief in its broadest sense of "stuff that happens in our minds", then of course the idea of an independent reality is entirely metaphysical. There's nothing that can happen in our minds that can possibly falsify a proposition defined to be absolutely uncorrelated with what happens in our minds.
But of course it is precisely this sense of "independence" that scientists are, by definition, entirely unconcerned with, at least in a professional sense. (We are no more concerned with their private opinions than we are with their tastes in food; scientists might typically consume large quantities of caffeine, but it seems unproductive to make such consumption essential to the definition of science.) The sense of realism entailed by these definitions is irrelevant to science; quite the contrary to the claim that science depends upon metaphysical objectivism or realism. As Hawking notes, science holds as foundational observations, which are, in the broadest sense, beliefs (at least when we state our perceptual experiences in words).
Clearly, some of our definitions have to be adjusted to make realism relevant to science. (Or we have to bite the bullet and say that science has nothing to do with reality... but then what does? Philosophy? Ha!)
Indeed our high-level, abstract (and perhaps naive) intuitions about reality deny this strong sense of independence: We can see and touch real things like rocks and trees. Moreover, we can actually manipulate real things: we can pick them up, put them down, break things, build things, etc. These are high-level intuitions, and therefore not a priori veridical (i.e. their content may be false), but they are authoritative: any good complete scientific theory must explain why we believe as we do. Whatever our intuitions about ordinary prosaic reality are, they do not include the strongest sense of "independence" and the broadest sense of "belief".
Can we productively take different — but not so different as to render our language unintelligible — definitions? It seems uncontroversial that we can talk about "independence" in a weaker sense, as being not absolutely but rather partially uncorrelated, and we can talk about "beliefs" in a more restricted sense, as certain kinds of things that happen in our minds.
(We have to take a little detour here, and note that "reality" and "objective reality" are not synonyms. In the sense of objective as "outside, or independent (even weakly independent) of the mind", to hold that "reality" and "objective reality" are synonyms denies that the mind is real, which is a... er... somewhat counterintuitive notion at the least. We have a trivial semantic problem with "objective" in the sense "truth-apt": Statements (in isolation or en suite) are truth-apt; it's at least vacuous and at worst meaningless to say that reality corresponds to reality. In the sense of "objective" as "determinably true", determinably would prima facie deny a metaphysical meaning.)
But... if we relax, even by a little, any of our definitions, our notions of reality and objective reality become falsifiable. If our notion of reality bears any sort of relationship to (i.e. has a dependency on) our observations, our perceptions, our experiences — i.e. our beliefs — then that notion is at least falsifiable (and perhaps even verifiable) by experience.
The most minimal construction compatible with science, "reality is that which 'causes' our perception," would seem metaphysical; it's an arbitrary definition, after all. But even then, this construction would be metaphysical if and only if we assert without justification in experience or belief in any sense that it is definitely true that something actually does cause our perception. But it could be the case that nothing can be found to have any sort of causal relationship (with "causal" defined non-vacuously) with our perception. It could be the case that simply listing out all our perceptual experience is the most compact way of "thinking" about them. In which case it seems unlikely that any mind — much less a mind capable even the illusion of linguistic communication — could possibly exist. In which case, the very presence of our minds confirms* that there is something does indeed cause perception). (Technically, it is the null hypothesis — that there is nothing which causes perception — that is falsifiable, falsified, and therefore justifies belief in the inverse.)
Likewise, we can falsify notions relating to objective reality in two ways: One is by noting that some of our beliefs can be determinably false: I can be mistaken, and discover I'm mistaken, that the Earth is flat (without substantively changing the meaning of the assertion. There are some truths that appear to be absolutely uncorrelated with some of my beliefs. Furthermore, we can observe that in certain, well defined circumstances, other people can "read our minds" by uttering the same words as we use to describe our internal experience. If my friend and I are standing next to each other looking at a tree, I can think, "I'm looking at a tree," and he says out loud, "You're looking at a tree." There are alternative explanations, but if we admit Occam's Razor — and why shouldn't we? One can hardly exclude Occam's Razor from science on either philosophical or sociological grounds — then these sorts of observations confirm and justify specifically objective reality (in all three senses listed above).
In short, that scientists — and everyone else — accept notions of reality and objective reality without (much) reflection can be explained not because they are "metaphysical" or in any sense a priori, but because they are falsifiable notions so well-established by ordinary experience that they can be reasonably accepted as true. Science does require some metaphysical assumptions (notably falsifiability as a demarcation criterion), but realism of any sort is not among them.