“Scientists inevitably make metaphysical assumptions, whether explicitly or implicitly, in proposing and testing their theories — assumptions which go beyond anything that science itself can legitimate. These assumptions need to be examined critically, whether by the scientists themselves or by philosophers — and either way, the critical philosophical thinking that must be done cannot look to the methods and objects of empirical science for its model. Empirical science at most tells us what is the case, not what must or may be (but happens not to be) the case. Metaphysics deals in possibilities … only if we can delimit the scope of the possible can we hope to determine empirically what is actual. This is why empirical science is dependent upon metaphysics and cannot usurp the latter’s proper role.” E.J. Lowe “The Possibility of Metaphysics” 1998 Emphasis in the text.
In part I we saw the ultimate question “what must be true for the universe of our experience to be the way it is?” can be framed with or without reference to consciousness. For a nontheist physicist or philosopher who assumes there is nothing more than physics to explain there remain questions whose answers, while remaining implicitly physical, nevertheless lay beyond what physics is qualified to address. Typically, these are questions about cosmological origins (the origin of the big bang, the cosmological settings, and the lawful regularities so well described in mathematical terms) or the fundamental ground of quantum mechanics. Also included here would be the origin of life though this in a more restricted way than the others.
Most physicists understandably ignore the matter of consciousness in their work. After all, the big bang, our present “cooled down” universe, and life, predate consciousness of any biological variety by billions of years. The universe presents much to be studied and many unanswered questions besides consciousness. But those questions too have metaphysical implications because questions themselves arise in consciousness and have implications lying outside the measurable qualities of the physical universe. Avoiding the issue of consciousness permits focus on a more restricted set of answers to the “what must be true” question at the cost (possibly) of biasing the set of reasonable answers against consciousness. What is necessary for the universe to be what it is apart from consciousness might no longer be sufficient if consciousness is added back in. Nevertheless there is, presumably, much in and about the universe whose metaphysical grounds do not demand any attention to consciousness other than implications arising from the process of explanation. The mechanisms of the physical after all are antecedent to consciousness, but their explication is not.
Physicalism, the metaphysical doctrine that physical processes and substances are all that exist in the universe simpliciter. Physicalism entails a denial of consciousness, that is, there is nothing in the universe that is non-physical. The apparently non-physical subject must be an illusion. The philosophical incoherence of such a stance should be obvious. Although many illusions have physical explanations (for example a mirage) even these are had by subjects whose purportedly illusory nature is left out of the explanation. How does an illusion have experience, or perhaps we should ask what precisely can experience be if illusions can have it? Nevertheless, many physicists and philosophers take physicalism seriously. But it is one thing to accept that a physical phenomenon must have a physical explanation, while being quite another, and metaphysically irresponsible, to declare there are no nonphysical phenomena.
Naturalism is the doctrine that explanations for all physical phenomena need refer only to physical processes and substances. By itself this does not entail physicalism, but typically naturalism combines with physicalism by insisting that only what can be explained physically is real. Most naturalists are also physicalists. Naturalism masks the possibility of the nonmaterial by suggesting to complete physical explanations for the physical means there remains nothing more to explain. Put another way, there is nothing left for the nonphysical to explain. Another implication commonly accepted by naturalists but not entailed by naturalism is epistemological in nature; namely that knowledge of the physical, and what may truly said of it, can be determined only by physical measurement.
Metaphysically speaking, naturalism divorced from physicalism, is on the most solid foundation as concerns our present grasp of universe phenomena. Even if one were to believe there is a teleological component (for example a God’s purpose) for the universe, a causally closed and intrinsically purposeless physical mechanism remains possible. Purely physical explanations for the physical can in fact be complete explanations while discounting any talk of purpose as redundant.
Materialism is the doctrine that while all phenomena in the universe (including consciousness) have purely physical antecedents, it is nevertheless possible for purely physical processes to result in what appear to be irreducible (to physics) nonphysical phenomena, notably consciousness. Materialism is not committed to physicalism except as concerns origins even if such phenomena are not conceptually reducible to physics. This is to say that materialists who are not physicalists are not committed to the idea that consciousness is illusory or unreal. Materialists are committed to naturalism as concerns the purely physical, but they concede that from the subjective side, a purely natural explanation for consciousness may not in principle be possible. Materialists reject the epistemological implication of naturalism, that knowledge can only be acquired of the physical by physical measurement.
Cutting across these metaphysical distinctions are the epistemological notions of realism and antirealism. Most scientists are realists (there is a special exception here for quantum mechanics where realism has a technical definition linked to hidden variable theories). They believe that there is a world independent of human subjective experience, and that subjective experience (coupled with measurement) accurately informs us about composition and processes of the independent world. If our best ideas (given realism) are not in any literal sense absolutely true about those constituents, they at least approximate this truth and gradually draw (perhaps asymptotically) to it as the scientific enterprise progresses. The most troubling metaphysical response from antirealists is that the connection between what we see in our heads and what is happening in the world independent of our heads seems magical or arbitrary. Realists point to predictions derived from measurement bearing out in the world. Airplanes fly. Antirealists rejoined that some set of incompatible natures might be true of the independent world that nevertheless allowed (or explained) the same outcomes.
The argument is important to scientific work because it bears on the interpretation of phenomena related to extreme or edge cases as concerns the present status of science. Realists point out that away from the edge cases, that is within our technological capacity to experiment, there are measurements from many different perspectives. The set of metaphysical possibilities entailed by any one overlaps those of others in such a way as to cancel all but a few possible ways the independent world could be. The answer to the “what must be true” question, at least as concerns the vast number of common phenomena, is mostly if not absolutely, fleshed in. While conceding that this is not a logical proof of correspondence between theory and world it is enough to persuade most scientists of the non-arbitrariness of the connection between the mental and independent physical whatever its underlying metaphysical reason.
Scientific method has a more technical term, “methodological naturalism”. Related to naturalism in that it is the methodology by which science earns naturalistic explanations. The process begins with physical observation and measurement of physical phenomena. From the observations, science develops theories and if possible, experiments to confirm or refute them. At least this is the traditional and still frequent approach that science takes. Scientists added another approach beginning roughly in the last half of the 19th century. Theories drawn from applying mathematics to the physical world became the foundation for either experimental or purely observational searches for the physical outcomes predicted by the theory or for other phenomena that ruled out those theories. The best theories, even before any attempt at confirmation or refutation are those that predict testable necessary outcomes. Philosophically, and at least as concerns strictly physical phenomena subject to physical tests, this all makes perfect sense.
That experiments or observations can confirm or refute theories about the physical world relies on the correctness (again the realist correspondence with the independent world) of a principle, the “Newtonian Paradigm”. This asserts that a given bounded or isolated system will behave like its unbounded (real) counterpart, if the environment surrounding the bounded sufficiently matches the conditions impinging on the isolated phenomenon when taken in its natural context. If all the physical causes, events, or states of affairs that impinge on a conceptually isolated physical subsystem are properly emulated in an experimentally isolated physical subsystem, the two will behave alike. What exactly constitute sufficient limits varies depending on the phenomenon under study.
Realist scientists accept that the success of the predictive power of methodological naturalism also means that we do manage to identify the appropriate boundary conditions much of the time. But not always. In the latter cases, experiments or observations are inconclusive and it remains for science to try again. The signal, the sign that a sufficient set of limits is found is the close match between unambiguous prediction of physical consequences and their experimental and observational confirmation.
There is another assumption implicit in the Newtonian Paradigm and that is that time is real and some part of the sufficient collection of limits that cancels out (typically though not always) because it applies equally everywhere. Every experiment and every observation takes place in time as do the phenomena themselves. That time moves differently in different reference frames is not much controversial these days nor should it be. But time nevertheless moves in the same direction in every reference frame except where, at the speed of light frame of photons and potentially other massless particles, time doesn’t move at all.
The Newtonian Paradigm and methodological naturalism only work to deliver explanations for conceptually isolated subsystems of the universe. If a system has no known boundaries, we cannot construct or even conceptualize suitable limits required by the Newtonian Paradigm. The physical universe, taken as a whole, is such a system. As observers in the universe, we have no grasp of possible impingement on the universe from outside it. There are a few good scientific theories about the origin of the physical universe; the origin of the big bang itself. ‘Good’ here means these theories make unambiguous physical predictions that are hypothetically observable by present (or soon to exist) instruments.
While strictly beyond the limits of the Newtonian Paradigm, all the good theories still rely on time’s reality, literally that time existed prior to the big bang. Theories that deny the reality of time or assert time begins at the big bang (or the illusion of time in consciousness is conceived as going back to the big bang) cannot possibly have physical consequences stemming from events or states of affairs before the big bang! Because they have no unambiguous consequences in the observable universe such timeless theories of the bang’s origin are, like much metaphysical speculation, open ended and utterly underdetermined by physical evidence. Multi-universes of varying types (see especially Max Tegmark’s “Our Mathematical Universe” (2014) for a very good review of them), colliding M-Branes, or a fortuitous (for us) fluctuation in the quantum vacuum.
Even if time remains real our theories do not reach to testable outcomes before the event of the big bang, only outcomes viewed in the aftermath of it. Unlike every other event from galactic formation to atomic decay the Newtonian Paradigm applies because we can observe and measure both what passes before and what after in time. As concerns the origin event of the universe there can be no unambiguous observation of the before because there was only one such event and it is now past. Our best theories might have observable consequences now and some of these narrow the possibilities of what was before. Because they all unambiguously rely on the reality of time, they confirm the reality of time!
Concerning another of the edge cases, the quantum realm, the situation with regard to the Newtonian Paradigm is a little different. We cannot be sure the limits of force and quantity that we apply with physical apparatus, are relevant to the quantum realm. This is not to deny that quantum phenomena are physical. But it may turn out that not all of what is physical is subject, in principle, to the measurement limitations of macroscopic instruments.
All of our instruments measure, one-way or another, by exchanging energy with the environment. We know that quantum phenomena result in energy transfer as their effects interact with our instruments. But unlike ordinary phenomena, bound in our experiments by emulating the energy exchange between them and that which is outside, we do not know, for the quantum realm, if any energy transfer occurs before interaction with our instruments. The instruments measure the outcome of quantum phenomena but not what happens prior to those outcomes. Although quantum systems are small, as with the big bang, we cannot view what happens to quanta before an energy exchange takes place. We can measure quantum outcomes, but not their causes or prior states-of-affairs. We do not know, as a result, what the relevant boundaries producing the effect are. As in cosmology, the upshot is an underdetermined plethora of theories lacking unambiguous predictions that would confirm or refute them.
One of the debates currently animating cosmology and impinging on the matter of cosmological origin has to do with the presence of infinities in the physical universe. Two kinds of infinities come up in cosmology, singularities, and the possible infinity of the universe as a whole. Infinities are mathematical constructs. If, like Max Tegmark (“Our Mathematical Universe” 2014) you believe the physical universe is a mathematical construct, then physical infinities are at least conceivable and ruling out their physical possibility is problematic if the universe’s governing mathematics necessarily includes them. Black holes might instantiate genuine singularities and, in the past, the big bang might have been a physical singularity. The universe might be infinite in extent.
Roberto Unger and Lee Smolin (“The Singular Universe and the Reality of Time” 2014) unhesitatingly declare there are no physical infinities. Despite the deep connection between mathematics and physics there is no observational evidence to support the idea that what is possible in mathematics must be possible in the physical universe. As deep as the regularities in physical process may go and so be subject to mathematical description, there is no guarantee that they go all the way to infinity.
Unger puts the basic issue this way: “Everything that exists in nature, including the universe and all of its phenomena and events, results from other events and phenomena in time. Everything, as Anaximander wrote, turns into everything else, under the dominion of time.
How then could the infinite come to exist, given what we see and know of the workings of nature? The universe might be indefinitely large, and some of its rudiments indefinitely small. Its history may extend indefinitely back into the past and far into the future. There is, nevertheless, and infinite difference between indefinite largeness or smallness and infinity, or between indefinite longevity and eternity, which is infinity in time.
No natural event analogous to an process that we observe in nature could jump the gap between indefinite largeness or longevity and infinity or eternity. … Consequently, the infinite could exist only if it always existed.” [Under/Smolin 2014 pp 315].
An epistemological argument that we, that is human observers, could never demonstrate a physical infinity by any empirical means and therefore never know there are (or were) physical infinities is as ironclad as an argument can get in philosophy rooted in science. We can never know, in the sense that science yields knowledge, if a physical infinity existed. By their nature all of our instruments, and any instruments we might conceivably build are finite and can measure only finite qualities and quantities. It cannot be possible ever to measure an infinity. In his “Hidden in Plain Sight VI: Why Three Dimensions” (2016) Andrew Thomas notes that no infinity has ever been observed in the universe. It is a safe bet that none ever will be seen. The epistemological argument precludes our ever observing infinity but not its metaphysical possibility. Alas Dr. Thomas did not address the question of whether an infinity instantiated in three dimensions was physically possible.
As concerns the infinite expanse of the cosmos, most cosmologists accept this argument for the limit of our possible knowledge and for other reasons tend not to believe the physical cosmos is literally infinite. But physics is less sure about the physical instantiation of mathematical singularities. Might there be an ontological argument against the possibility of physically instantiated singularities? Since there could be no experimental measurement of infinity we cannot know if any particular property or combination of properties of the observed universe is (or are) an entailment of a physical infinity. If we derived entailments, necessary effects of a physical infinity mathematically, and they turned out to be physically impossible, we would have strong ontological reasons to reject the possibility of physical infinities.
We divide possible singularities into two types; singularities which might exist at the center of black holes, and the [possible] singularity of the only “white hole” in our universe, our big bang. It seems reasonable to link the hypothetical infinity of the present material universe to that of the big bang. Could an infinite universe proceed from anything less than an infinite initial event? If the big bang was not infinite (as Unger, Smolin, and many other cosmologists for various reasons now believe) then the material universe, however great its extent must also in the end be finite. If we can rule out the infinity of the big bang we also rule out the infinity of the cosmos.
What would be the effect in the physical world of a physical infinity at the center of a black hole? We can measure the size of a black hole’s horizon, also its mass, spin, and charge. None of these is infinite. As concerns real cosmological phenomena, black holes and the big bang, differentiated matter-energy destroyed by the extraordinary physical conditions of these events leaves but three broad properties to consider, density, temperature, and pressure. Would there not be measurable physical effects of an infinite quantity of any or all of them? Can a physically instantiated infinity have subinfinite physical effects as measured at some distance from the infinity? What does distance from infinity mean for a physical universe of three observable dimensions? Could the present universe we observe today coexist with instantiated infinity?
The physics and cosmology I’ve read is not encouraging. If the mathematics of relativity did not point at infinity this debate would not be continuing. Some physicists do believe the math signals something that exists or at least might have existed. Equally many note there is (indeed can be) no physical, empirical, evidence that all mathematical expressions represent phenomena in time. Yet in all the literature I’ve explored no one has addressed the question of the physical implications of instantiated infinity.
Some theories enable physics to dismiss the matter. One approach is to declare that at infinity the normal regularities of pressure, temperature, and density simply vanish. As a result, there are no finite physical effects of infinity. Of course there is no empirical evidence (nor could there be for epistemological reasons noted above) that such an unintuitive outcome should hold and if it did, the presence or absence of instantiated infinities could not be distinguished. There aren’t any testable results that would support any distinction.
String theorists might suggest that instantiated infinities are confined to compactified unobservable dimensions. As such they have no implications, that is necessary consequences, for the four dimensions of spacetime in which we live. In Fashion, Faith, and Fantasy In the New Physics (2016) Rodger Penrose challenges the view that events in string theory’s compactified dimensions would have no implications for the stability of our spacetime. Either way string theory is not helpful here. If Penrose is right, then infinities cannot hide in compactified dimensions. If he is not right, the possibility of infinities hidden in compactified dimensions is redundant as concerns the physics of the observable universe. As with vanishing properties their existence has no testable (confirming or refuting) outcomes. We are returned to the basic question; what would be their effects if they existed?
Even if black holes contain no singularities the question of the big bang and the potential infinity of the universe remain. A hypothesized physical infinity at the big bang suffers from some of the same potential problems as physical infinities in the center of black holes. As space expanded following the big bang event the radiation cooled yielding, in temporal order, nucleosynthesis, and then (380,000 years later) neutral atoms leaving behind the light we now see as the Cosmic Microwave Background. But why would a literally infinite big bang ever cool? Wouldn’t an infinite singularity supply an infinite amount of heat and pressure (gravity possibly nonexistent in the absence of anything with a rest mass)? Why would we expect the universe to cool no matter how much (or for how long) it expanded? In mathematics if you subtract 1 or even infinity from infinity, you still have infinity. If one is going to hypothesize a literal physical infinity would it not have to behave as its mathematical counterpart? If it did not, on what basis could we claim that it was infinite?
Is what follows from the hypothesis of a physical universe of infinite extent coherent? A few philosophers have explored consequences of the idea (an infinite number duplicate yous living lives on duplicate Earths, regions of the universe filled with mint jelly, Boltzman brains, etc). Most cosmologists do not believe the physical universe is infinite. Present models of the universe’s origin do not infer infinite quantities of matter-energy. The universe did cool as it expanded; evidence, if anything is, of a subinfinite big bang. While not a knock out argument, it is consistent with the general assumptions of the Newtonian Paradigm that we ignore what is not needed in an explanation. We’ve met the redundancy of infinity in all the hypotheses claiming that instantiated infinity has no unambiguous outcome in the physical. The same applies to an infinite expanse of matter-energy. It is redundant as concerns any observed phenomena.
Unger sums both epistemological and ontological issues this way: “The problem in supposing the world to be infinite or eternal, or both, is not just that we could never know that the world is infinite or eternal, given the infinite difference between indefinite largeness or longevity and infinity or eternity. The problem is also that the overall character of nature would be at odds with nature as we encounter it piecemeal, through science as well as through perception.” [Unger/Smolin 2014 pp 317].
Solving the riddle of infinities, either ruling them out, or showing their necessary existence, would tell us if mathematics grounds natural law or merely describes it. If mathematics controls what happens, then we live in a universe in which time emerges from interacting a priori timeless abstract structure and physical infinities are coherent. If mathematics merely describes the universe then time is real and fundamental, a primitive ingredient of a historical unfolding and there are no physical infinities thanks to the infinite gap between indefinitely large, small, long, or short, and infinity. But that gap does not address physical consequences of physical infinities should such exist. Unger notes that we cannot measure any infinity inside the explorable universe, but he directs his argument through epistemological considerations at the incoherence of physical infinities rather than the impossibility of their outcomes.
Unless physicists conclude for theoretical reasons (as there never will be any empirical reasons) that there are (or would be) consequences to physical infinities that are physically impossible (that is antithetical to all that we see), the metaphysical argument alone is not sufficiently strong. It cannot be because without that demonstration our theories can accommodate what we see with or without infinities. The metaphysical argument is suggestive and perhaps helpful if it puts physicists on the track of some theoretical examination of the physical outcomes of physical infinities, but it does not resolve the matter of infinities by itself. It cannot as long as alternate possibilities remain conceivable.
Not everything that is conceivable is physically possible though it might well be logically possible. This is an important distinction that epistemology and metaphysics presents to physics. It is important because the debate over infinities rests on the conceive-ability of the alternatives. A “knock out” argument against infinity rests on discovering the physical impossibility of their outcomes under conditions in which no empirical determination of that impossibility is possible. The track record of even theoretical physics is inconclusive here. It is possible (again logically conceivable) that at infinity all the physical laws we know are suspended or that instantiated infinities hide in compactified dimensions. In those cases, a physical universe containing physical infinities would look no different from our universe today if for no other reason than any consequence (including none) of a physical infinity is possible and nothing can be ruled out. If the mathematics did not already point to infinities, cosmologists wouldn’t be having this debate.
In 1998 William Dembski published “The Design Inference: Eliminating Chance through Small Probabilities”. He followed, in 2001 with “No Free Lunch: Why Specified Complexity Cannot be Purchased Without Intelligence”. His subject was not the cosmically large or the unreachable smallness of the quantum domain, but the origin and evolution of life. Living organisms fall comfortably midway in size between cosmic and quantum scales. Life presents itself in clearly bounded subsystems open to investigation by science. Biology rests on chemistry and chemistry on physics. Advances in the biological sciences through the past century show the applicability of the Newtonian Paradigm to life. In the 19th century Darwin’s theory of [biological] evolution provided a ground for explanation of life’s evolution, but never its origin. Even as concerns evolution however, Darwin’s work is incomplete. Some of its predictions are well confirmed by experiment and observation, but not all of them.
The problems here are not those of the very large or vanishingly small. They do not involve impossible measurements of infinity or phenomena that exchange no energy. Like the cosmos, we cannot observe the origin of life on Earth in the deep past. But there is no logical reason we could not watch life’s origin on other planets, or reproduce the phenomena in the laboratory. To date we have achieved neither. Rather these problems stem from the dramatic difference in the information content of living organisms compared to any nonliving subsystems of the universe.
Darwin’s theory asserts the environment of any given time selectively filters random changes in life’s information content. Changes inimical to an organism’s survival in its [then] environment are eliminated because those organisms (and those changes) fail to reproduce. By contrast changes that, by chance, happen to make the organisms reproduction more likely are added to the sum total of information present in that organism and its descendants. It was Darwin’s contention that information present in today’s living organisms was thus slowly assembled over the billions of years of evolution on Earth.
That evolution does take place is today indisputable, but all the observed examples involve a reshuffling of existing information, not the selective collection of new information. No one has witnessed the evolution of a more complex organism from a simpler ancestor. Although such development, increasing complexity achieved accidentally, is not precluded by the laws of physics, Dembski’s work casts doubt on the probability of accidental changes generating the sheer amount of complexly specified information in the variety of life on Earth even over the course of a few billion years.
The same considerations apply to the origin of life from nonlife. The information gap between even the most complex nonliving and the simplest unambiguous life is enormous. Modern biological science has proved there is nothing unnatural about life, only matter-energy in an extraordinarily fine-tuned balance behaving in accord with the laws of physics. I bring up the problem that Dembski poses to physics because it is an example of another blindness to metaphysical implications of physical phenomena present in modern science.
Dembski does not claim the “Abrahamic God” created life and fostered its evolution to present forms. What Dembski shows with mathematical rigor is that life’s origin and present status are unlikely to have occurred by chance. Chance is statistically, but not absolutely, precluded Of course Dembski does believe that life and then evolution as we have come to experience it, if it is not the result of random chance must be, in part, the product of some intelligence. The intelligence need not be God, but something antecedent to life on Earth is surely entailed. There is nothing in Dembski’s core assertions that rules out a physically embodied designer, an alien intelligence, or some form of anomalous monism.
It is to the great shame of the modern scientific community that the implications of Dembski’s work are not at least properly understood and followed out. He is accused of having made no testable predictions, but the core of his work is not a theory but an observation. His observation concerns information, its quantity and quality (what Dembski calls “specification”). Present scientific consensus does not dispute the values with which he begins. Theirs is strictly an irrational (and emotional) rejection of the implications of Dembski’s observation. He may even be wrong! To decide someone will have to replicate his work and show where he makes his mistake. No one in the scientific community has taken on that task.
Physics often accuses philosophy, particularly metaphysics, of painting “castles in the air”. I have shown that physics, tied down by the physicalist assumption, paints many of its own castles whose only qualification for admission to the ranks of physical theory is that their imagined objects are physical. That such objects exist is no more demonstrable or refutable than the existence or nonexistence of God. But physics correctly establishes a universal characteristic of the physical world. The Newtonian Paradigm works when appropriately applied because the mechanisms of the physical are blind and not teleological. That this insight is the basis of a false induction, that there is no teleology imposed from outside the physical, is beside the point. Anomalous monism is false.
The only evidence of teleology in the physical world comes from cosmology, the values of the cosmological settings. All the cosmological “castles in the air” are unverifiable tries to escape the teleological implications of those settings. The settings define the entire landscape of the physically possible in our universe. On this, at least, scientists are agreed. Galaxies and living organisms are possible. A universe of mint jelly is not. The mass-energy of the big bang, given these settings, sets up the regularities of “natural law”. Physics and cosmology have well shown that these alone are sufficient to structure the universe down to the planets and their atmospheres. What physics has not demonstrated is that these regularities alone are sufficient to jump the information-gap between nonlife and life, or that they fully account for the accumulated information we see in the living world around us. If they are inadequate to these two tasks, they cannot be sufficient to explain subjectivity emerging from life.