Against common sense, people can believe some very strange things. One marvels at the ingenuity of the human imagination—not only the things that make practical sense, like houses, agriculture, technology—but above all the things that make little sense to a rational mind, like gods and demons, superstition and magic. Yet, religion and magical thinking have characterized human culture far longer than what our secular culture now defines as rationality.
The ancient Greeks we admire as paragons of rationality seem to have actually believed in their pantheon of rowdy and absurdly human-like gods. The Pythagoreans believed in sacred numbers and the transmigration of souls; they used mathematics and music for mystical purposes. Plato believed in a metaphysical realm of Ideal Forms underlying material reality. Copernicus thought the planets must move in perfect circles, because the circle was the symbol of perfection; and Kepler thought that angels moved the planets along their (elliptical) orbits. The early scientists were literally alchemists and Creationists. There are scientists today who believe in the Trinity and the transubstantiation of the Eucharist. My point here is not to disparage religion as superstition, but to marvel that superstition can exist at all.
Language confers the nearly magical power to define things into being—as we imagine and wish them. Outrageous beliefs are possible because a story can easily be preferred to truth. A story can make sense, be consistent, clear, predictable and repeatable. Reality, on the other hand, is fundamentally ambiguous, confusing, elusive and changing. Reality only makes sense to the degree it can be assimilated to a story. It made sense to many ancient cultures that a year should have exactly 360 days (corresponding neatly to the 360 degrees of the circle). The fact that the daily rotation of the earth on its axis has no physical relation to the time it takes to move around the sun was a great inconvenience to calendar makers over the ages, who knew better than nature how the world should work.
In general, what we consciously experience as real is the result of sensory input that has been assimilated to a story that is supposed to make sense of it, and upon which an output can be based that helps us live. The story does not need to be true; it only needs to not conflict with the existence of our species. That gives a wide latitude to imagination and belief.
The brain is a delicate instrument, normally tuned to the needs of the body. Like a complicated machine, there is much that can go wrong with it. Being so complex and malleable, it is also capable of great variation among ostensibly similar individuals, which can include behavior that deviates far from what serves the body or serves the species. Underlying all variation or dysfunction, however, is the natural faith we have in experience. We naturally tend to believe whatever our minds present to us. Human freedom consists in the ability to be wrong while utterly convinced that we are right.
Addiction is an obvious example of the compelling attractiveness of some stimuli—such as alcohol, drugs, or sex. It is natural to seek pleasure and try to avoid pain, because these represent the state of the organism, which tries to maintain itself. However, when experience is sought for its own sake (rather than for the body’s sake), the link with wellbeing is broken. We can then find pleasure in things that are bad for the body (and society), and reject things that are good for it. Of course, we have extended such meanings to include intellectual pleasures and emotional suffering as well. In fact, humans can abstract experience in general, away from its ties to the body, so that it becomes a sort of private entertainment to pursue for its own sake, apart from its relevance to bodily or social needs.
Other compulsions, such as obsessive behavior (including avoidance as well as attraction), further demonstrate the mind’s willingness to believe its contents. And then there is artificial input, applied with electrodes to the brain, for example, which can stimulate specific experiences or memories. Or applied by means of transcranial magnetic stimulation, which can change your perception, for example altering the apparent color of things or draining them of color altogether. On the other hand, sensory deprivation causes outright hallucination, as the brain makes up its own experience in the absence of sensory input.
Depending on the circumstance, we may either believe, or have reason not to believe, a given experience. If you know you have wires stuck in your head, you may justifiably be suspicious of your experience. On the other hand, if you have ingested a psychedelic drug, or have an unsuspected brain tumor, it may affect your judgment as well as your perception, and you may fail to disbelieve your hallucination. It is helpful to keep in mind that the brain hallucinates all of the time; while some of the time its hallucinations are dominated and guided by bona fide sensory input. We then call that reality and feel justified in believing the hallucination.
Within the framework of normal perceptual reality, we also have thoughts and feelings that we feel compelled to believe. Social media now run rampant with outrageous claims and memes, endorsed by our natural willingness, as social creatures, to believe what others tell us. Again, this reflects the power of language to evoke mental images and feelings, in a socially approved form of hallucination, to which we tend to accord the same credibility as we do to first-hand perceptual images and the feelings they arouse.
Even in the most abstract realms of speculation, we tend to have faith in our mental constructs. Often that faith is justified, at least provisionally, as a useful tool that can be updated by further observation and experiment. In the seventeenth and eighteenth centuries, scientists believed in a substance called phlogiston, released as heat during combustion. This concept was superseded by the caloric theory, which conceived heat as a sort of fluid. That idea was abandoned in favor of heat as a form of energy—whether the kinetic energy of molecules or the radiant energy of electromagnetic “waves.” Energy, in modern treatments, persists as a kind of substance interchangeable with mass (as per Einstein’s famous formula). What is actually involved, in all cases, is tangible measurement in specific contexts, not some ethereal quasi substance. But to reify energy conceptually seems to be useful in physics even though “it” manifests in such diverse forms and consists in no more than measurable quantities. (Not to mention nebulous popular metaphysical notions of “energy,” such as chi.) Even more derivative abstractions, like entropy and information, are now reified as quasi-substantial, attributed their own causal powers. Even the measures we call space and time are reified—for example, as the 4-dimensionsal spacetime continuum.
To objectify is a built-in tendency of the mind. After all, our primary orientation is toward objects in space. We literally experience the world as a real space outside our skulls, filled with interacting things. Since language and thought are essentially metaphorical, it is natural (if not logical) for us to think of abstractions—indeed, anything that can be named—as at least vaguely substantial. We ontologize everything, more or less automatically (just as I am now, admittedly, ontologizing the compulsion to ontologize). The fact that this compulsion includes reifying experience as ‘mind’ or ‘consciousness’ leads to the infamous Mind-Body Problem, as we then ponder what sort of thing it must be, compared to physical things. Descartes posited a dualism of physical thing and “thinking thing.” Others, before and since, have proposed some monism or other instead: that everything is material, that everything is mental, or that mental and physical amount to the same “thing.” Underlying these isms, concerning what is ultimately real, remains the fundamental need to be settled about something that seems substantial.
The dualism above may turn out to be little more than a built-in feature of our nervous system, which provides us with two radically different points of view. The myelinated exteroceptive nervous system is the basis for the experience of an external world of objects in space and “digital” judgments regarding them. Through language, we conceive a “third-person” point of view based upon that experience of a world of publicly accessible objects. But the body operates also with a more fundamental unmyelinated nervous system, responsible for feeling, valuation, and homeostasis. It operates in a more analog mode to monitor the body’s needs and regulate its state. We identify these aspects with a “first-person” point of view, in which qualia and feeling are the chief features and seemingly private. Evolution has thus provided us with two minds, so to speak, which have in common the need to believe what they present.