“When the lower part of the trunk dies, the higher parts die too. Death spares no limb.”
Victor Hugo, The Man Who Laughs
Theoretical physicists today claim that their often-bizarre ideas are strongly supported—in some cases even proved—by observed facts. After all, they are not a band of mystics or skeptics hell-bent on rejecting the existence of a real, intelligible physical world. They are scientists, and they must accept whatever conclusions follow from the facts. If they have rejected the reality of a world independent of consciousness and the principles of identity, causality, and logic, it is only because scientific objectivity required them to do so.
Does the motion of a body through some physical substance in space cause its length to contract? Is a clock slowed by its motion through this substance?
Let’s examine this claim by means of a hypothetical exchange between a layman (L) and a physicist (P). The layman is questioning the physicist in an effort to understand the scientific evidence for the strange new ideas he has heard.
L: “Let’s begin with quantum physics. It would help me if you could describe your observations of these odd particles that exist without specific properties, or with contradictory properties. What do they look like?”
P: “Well, we haven’t actually seen them. Whenever we look, they turn into something with definite, non-contradictory properties. But they were nothing in particular before we looked; it was only our act of observing or measuring them that created the specific properties we observe.”
L: “Then perhaps you could describe the scientific evidence for this mysterious process by which our act of observation turns a ‘nothing in particular’ into a real something. How does it work?”
P: “Unfortunately, we know nothing about it. Many prominent physicists, including John von Neumann and Eugene Wigner, have taken the view that the mind somehow creates the objects of awareness. But, if so, it isn’t the physicist’s job to explain how, since we don’t study the mind.
“Other physicists argue that it isn’t the mind per se, but rather the act of measurement that creates the specific property measured. But, if so, there’s nothing in quantum theory to describe how the ‘creation process’ works. A few physicists regard this as a weakness in the theory—they call it the ‘quantum measurement problem.’“
L: “I still don’t understand. If you observe only specific entities with definite properties, and you know of no mechanism by which an inconceivable ‘nothing in particular’ could suddenly acquire such properties, why not accept the fact that these things possess real attributes before the observation?”
P: “Because we’ve concluded it isn’t possible to develop a theory that explains our experimental results in terms of entities with specific, non-contradictory properties.”
L: “How was that conclusion reached? Have physicists been trying to think of such a theory, only to give up in despair after a century of frustration?”
P: “Well, no. The founders of quantum theory opposed such efforts from the outset. They told us there is no intelligible reality underlying the quantum observations, and we don’t want to waste our time thinking about something that doesn’t exist …”
The layman, feeling unsatisfied and slightly exasperated, decides to put quantum theory aside for the moment, and turns to relativity.
L: “I would like to understand the ideas of ‘length contraction’ and ‘time dilation’ in relativity theory. Are these real physical effects? Does the motion of a body through some physical substance in space cause its length to contract? Is a clock slowed by its motion through this substance?”
P: “There was a theory that treated length contraction and time dilation in that way. It was proposed by a Danish physicist named Hendrik Lorentz. On the basis of his theory, Lorentz derived some of the fundamental equations of relativity before Einstein did. But the Lorentzian theory was rejected and replaced by Einstein’s theory.”
L: “Was Einstein’s theory accepted because it was better able to account for the observed facts?”
P: “Not exactly. The basic advantage of Einstein’s theory is that it’s simpler. He dismissed the idea of explaining the phenomena of relativity by reference to any physical stuff in space (the so-called ether). Instead, we just say that moving bodies appear shorter and moving clocks appear to run slower—as perceived by a stationary observer. In other words, space contracts and time dilates by amounts that depend on the relative motion with respect to an observer.”
L: “But I want to understand the cause of these effects. You say that length contraction and time dilation don’t refer to real physical changes in moving bodies. Do they instead refer to real effects on our measurement of lengths and times? I remember hearing a classical physicist explain that heating a ruler causes it to expand and thereby affects length measurements. Does motion also affect our physical means of measuring lengths and times? If so, I could make sense of relativity theory. There would still be real lengths of bodies and real time intervals; we merely have to account for and subtract the effects of motion on the measurements. After all, the actual properties and relationships of other bodies can’t change whenever I decide to move!”
P: “You’re missing the point—and failing to grasp the advantage of Einstein’s theory. Why do you insist on an explanation in terms of physical entities that exist independent of an observer’s perceptions? Relativity theory is simpler, and therefore superior, precisely because it avoids reference to such entities. Einstein recognized that the sole purpose of a scientific theory is to describe and predict our perceptions.”
L: “Perceptions of what?”
P: “That is a question that belongs to the old era of classical physics. We don’t ask it anymore.”
L: “Was it scientific evidence that convinced you to settle for describing ‘appearances’ rather than seeking physical explanations?”
The physicist answers in the simplest manner possible: he shrugs and walks away.
The science of physics cannot be pursued in a cognitive vacuum; it necessarily depends on a base of more fundamental ideas.
The “observed facts” that support these strange ideas are like the new clothes of the emperor in a famous children’s story: they are non-existent. Relativity theorists cannot cite observational evidence of the alleged properties of space and time—because such properties belong to entities, not relationships. They cannot support their view that the goal of physics is merely to describe “appearances,” rather than investigate the nature of the physical world—because we don’t perceive “appearances,” but physical things in the external world (in a form which depends on the nature of our sense organs). Quantum physicists cannot cite observations that support their rejection of identity and causality—because every observation is an observation of specific entities acting in strict accordance with their specific natures; there is nothing else to observe. There can be no scientific evidence for the “measurement miracle”—because miracles are incompatible with the essence of science, which seeks causal explanations. There can be no evidence for consciousness creating the objects of awareness—because consciousness is the faculty of perceiving reality, not creating it. There can be no arguments in favor of accepting “complementary” contradictions—because one cannot use logic to invalidate logic.
Where did physicists get such ideas, if not from scientific evidence?
To grasp the answer, one must first recognize that the science of physics cannot be pursued in a cognitive vacuum; it necessarily depends on a base of more fundamental ideas. A physicist will accept the goal of grasping the nature of the independently existing physical world—only if he accepts that there is such a world, and that he perceives it, rather than perceiving a shadowy world of subjective appearance. He will search for the causal laws governing nature—only if he accepts the law of causality, and rejects the view that things can act apart from or in contradiction to their natures. He will require that his theories ascribe specific, non-contradictory properties to physical entities—only if he accepts the law of identity and the principles of Aristotelian logic. He will demand that his theories derive from observational evidence—only if he accepts the wider principle that abstractions of any kind derive from perceived concretes, and he therefore rejects claims based on arbitrary guesses or “intuition.” He will chose rationally between competing theories and eventually be able to prove his theories—only if he accepts rational standards of proof and believes himself capable of achieving certainty. He will hold to the independence of his scientific judgment—only if he recognizes that truth is the correspondence between ideas and facts, and not, for example, a “consensus of the scientific community.”
Such fundamental ideas—dealing with causality, identity, logic, certainty, truth, and the basic relationship of existence to consciousness—are indispensable to physics, yet not part of the subject matter of physics. They are studied by another science.
The science of fundamental ideas is philosophy. Physics is built on a foundation provided by two of its branches: metaphysics and epistemology. Metaphysics deals with the nature of existence as a whole, or, in Aristotle’s words, with “being qua being.” It identifies, in terms of the broadest essentials, what kind of world we live in. Metaphysics answers such questions as: Is the universe a realm of real entities with specific natures, or is it a realm of pseudo-entities that can exist without identity? Is it a causal realm ruled by natural law, or a realm of inexplicable miracles ruled by a supernatural power, or an unintelligible chaos ruled by chance? Is it a realm of objects that are what they are independent of anyone’s consciousness, or is it a realm of illusion created in the mind of the subject? Are the facts of reality absolute, or do they change with our perspective? Is the universe eternal or did it spring into existence as a product of supernatural ideas?
Men cannot decide how to act without adopting a view of the world in which they live and a theory of how to gain knowledge of that world. This is true despite the fact that most men do not think about philosophic questions in explicit terms.
The basic view of the world held by physicists is contained in their answers to such questions—and different answers lead to very different theories of physics.
“Epistemology” is the branch of philosophy that studies the nature of knowledge and man’s means of acquiring it. It answers such questions as: Do our abstract ideas derive from our perception of particulars in reality, or are such ideas, as Einstein claimed, “free inventions of the human mind”? Do abstractions refer to real things, or arbitrarily selected groups of “mental images”? What is logic—an objective method enabling us to identify facts without contradiction, or a linguistic game with rules set by social convention? What is truth—the correspondence between an individual’s ideas and the facts, or a consensus of belief among the members of some group? Can we know reality by means of reason, and if so, how? Are there means of acquiring knowledge other than reasoning from the data provided by our senses, such as innate ideas, intuitions, revelations, feelings, etc.? Can reason yield certainty, or are we doomed to perpetual doubt?
A physicist’s view regarding his basic goal, and his means of achieving it, depend on his answers to these questions.
The power of these primary branches of philosophy is inescapable. Men cannot decide how to act without adopting a view of the world in which they live and a theory of how to gain knowledge of that world. This is true despite the fact that most men do not think about philosophic questions in explicit terms. Such men do not manage somehow to live without any answers to these questions; rather, they absorb their eclectic views from others, while giving the issues little if any thought. Although only a small number of men originate philosophic ideas, the ideas are disseminated throughout the culture in countless ways by schools, , churches, the media, and the arts. They are implied more often than explicitly stated, but years of such implications leave an indelible impression.
The power of philosophy is sometimes hidden, but always real.
But the power cuts both ways. Irrational philosophy has put theoretical physicists into a restless sleep, closing their eyes to the questions they should be asking. Rational philosophy can awaken them from this long nightmare—and make possible an endless series of exciting discoveries.