Physicalism is the philosophical thesis that everything is physical and that there is nothing other than the physical. It means nothing exists that is not physical or that cannot be explained or attributed to the physical.
What is physical?
One difficulty of the physicalist view is identifying exactly what is meant by, "physical." There are at least three different ways of understanding what is meant by the physical:
1. The physical is all that is studied and identified by the sciences, especially physics.
2. The physical is all that can be directly perceived, that is, seen, heard, felt, smelled, and tasted, or can be discovered by examination of what is perceived, directly or indirectly.
3. The physical is all that has properties that can be measured, for example: mass, momentum, size, shape, temperature, charge, capacitance, conductivity, hardness, inductance, impedance, length, location, volume, magnetic field, electrical field, and many more.
Whichever view one takes of the meaning of physicalism, the essential meaning is that the existence that is directly perceived and studied by the sciences is the only existence there is, has the nature it has, is not contingent on anything else, and everything that can be known can be explained as an aspect of that physical existence. That physical existence is what is meant by, "natural," or, "ontological," existence. It means there is no supernatural, mystical, or ineffable existence.
It is that view of existence which is mine, but I cannot agree with the physicalists, because they have turned that rational view of existence into a kind of mystical religion of its own.
What Is Right About The Physicalist View?
The physicalist view is primarily a rejection of any form of mysticism or supernaturalism. It is essentially the view that nothing can be known for which there is no objective evidence that can be verified by anyone.
There are three specific points made by physicalists that are true:
1. The physical universe is all there is. There is nothing that exists that is not physical or that has no physical properties.
2. Physical existence is not contingent on anything else. There is nothing that precedes physical existence, causes physical existence, or determines what it is beyond physical existence and its nature itself.
3. There is no other kind of material than physical material. There are no entities or substances that are not physical. There are no supernatural, spiritual, or ineffable existents or substances.
What Is Wrong With The Physicalist View?
The physicalist view is called, "monism," (there is only one kind of existence) to distinguish it from views, such as, "dualism," that assume existence includes more than one kind of existence, such as non-physical entities, non-physical substances or anything the physical is contingent on. It is a tacit rejection of any form of the supernatural (souls or angels), non-material beings (gods or demons), or devisions in the properties of natural things such as, "mind and matter."
The rejection of the supposed mind/matter dichotomy is, perhaps, the most important of the physicalists positions, because the belief that consciousness or the human mind are a kind of substance or entity that is non-physical is widely believed and promoted by every religion and mystic ideology. It is those kinds of superstitious beliefs that physicalists are most against.
Unfortunately, in its zeal to reject all forms mysticism and supernaturalism, physicalism rejects much of the evidence of physical existence on which physicalism is founded. All that is known or knowable about physical existence is known only because human beings are able to perceive physical existence. If human beings did not see, hear, feel, smell, or taste the physical, there would be no way to be aware of any existence at all, much less what its nature is.
Most physicalists, however, deny that consciousness exists, or, if it exists, it only exists as something produced by the physical, such as a property that, "emerges," from the activity of the brain or neurological system.
Why Physicalists Reject Consciousness And Mind As Existents
Physicalists deny that consciousness, and that unique consciousness of human beings, the mind, exist as anything other than manifestations of physical behavior. If they existed in any other way, they would not be physical existents, it is presumed. Consciousness and mind cannot be physical entities or substances for three reasons:
1. Consciousness and mind have no physical attributes at all: no mass, momentum, size, shape, temperature, charge, capacitance, conductivity, hardness, inductance, impedance, length, location, or volume.
2. The physical is all that can be perceived, but consciousness and mind cannot be seen, hear, felt, smelled or tasted. They cannot be detected at all in any other creature.
3. Since consciousness and mind have no physical properties there is no way they could influence, much less control, physical behavior. Volition would be impossible because a non-physical mind could not cause physical behavior.
There are other reasons physicalists reject the idea of consciousness and mind being anything more than the result of physical behavior, but these are the primary ones, and, I think, valid. But there is a mistake here. Consciousness and mind are not entities or substances.
Consciousness and mind are attributes of living organism. Living organisms are physical entities with the unique attribute life. Organisms are designated organisms because they are different from non-living entities and it is only organisms which can have the attribute of consciousness or mind.
Physicalists regard life in the same way they regard consciousness and mind, as nothing more than the manifestation of physical behavior. Life, like consciousness and mind, is not a substance or existent, however, but an attribute of those entities that exhibit behavior that only living organisms are capable of. The behavior of a living organism sustains the organism as the kind of entity it is, which no non-living entity does. In all of the physical sciences there is no explanation of why an entity should behave in a way that sustains itself as the kind of entity it is. Only living organisms manifest that kind of behavior.
Living behavior involves two aspects of the organism, internal and external. The internal aspect is a continuous process by which the organism maintains itself as the organism it is. It is called the life process.
That living behavior requires another unique attributes, sentience. A non-living physical entity will react to the presence of other entities, but that reaction will be a purely physical reaction. An organism's living reaction to the presence of other entities is call a "response," the other entities are called, "stimuli." Responses to stimuli are not the same as a non-living physical reactions to an external influence.
The "response" of a living organism to outside influences is an action made possible and required by the life "process" of the organism. If for any reason, the life process should cease, that response to stimuli would cease, even though all the physical attributes of the entity remain the same. It is the process itself that reacts to the stimuli, indicating the process detects the presence and nature of the stimuli in order to react to it.
If an organism could not detect a stimulus, it could not respond to it. If an organism could not distinguish the differences in stimuli, it would react in the same way to all stimuli, or react randomly without any connection between the nature of the stimuli and the action. This is what distinguishes a physical reaction from a living response. A response is the result of the organism in some way detecting (not identifying) the presence and nature of the stimuli, unlike a mere physical reaction which is an immediate action attributable directly to the external influence and laws of physics (even if the reaction is a very complex one involving a computer program, for example).
The particular stimuli an organism will respond to and the specific response the organism makes is determined by the organism's nature as an organism, that is, an organism's reactions to stimuli will be appropriate for sustaining the life process and the organism as the kind of organism it is. If the life process ceases, the organism reverts to being a mere physical entity, and its behavior reverts to that of any other non-living entity, including its reactions to external influences.
Life And The Physical
A living organism is a physical entity. There is no such thing as life independent of the physical organism it is the life of.
All of the physical behavior of an organism conform to the laws of physics and the physical (chemical and medical) sciences. No living behavior violates any law of science.
There is no physical scientific explanation, however, for why an entity should behave to sustain itself as the kind of entity it is or why it should be able to detect and determine what other entities are in order to be able to react to them. No physical or chemical principle requires any such phenomena. It is a unique physical phenomenon.
Physicalists cannot (and do not) deny consciousness outright. They cannot deny consciousness without denying the basis of physicalism itself, which is an existence that one can be aware of. Physicalists deny that consciousness is anything more than some kind of physical process or the product of a physical process. No physical process can account for consciousness however.
Consciousness is an attribute of physical living organisms and does not exist independently of the individual living organisms it is the consciousness of. There are three attributes of consciousness that make it impossible to explain in merely physical terms:
1. Conscious only exists as an attribute of individual organisms and cannot be perceived by any other organism or detected by any physical means.
2. The consciousness of an individual is one and the same consciousness so long as the organism lives.
3. There is only one consciousness that is simultaneously and continuously conscious of all that is seen, heard, felt, smelled, tasted, felt internally, recalled from memory, and in humans, is thought or imagined.
[NOTE: Such a phenomenon is not physically possible. For every individual has only one consciousness, which conscious of what one is thinking, perceiving (internally and externally), and what one is feeling emotionally, as well as conscious of all the other things one is aware of, simultaneously and continuously.
It would be impossible, at the physical level, to make all the discrete physical events required for detection of separate phenomena be a single event. What that means, is, there is no physical system which is able to detect sounds (microphones, for example) images (a video camera, for example), pressure and weight (a transponder system, for example) temperature (an electronic thermometer for example), movement (an electro-gyroscope for example) which can all be recognized in all its detail as a single event or process. The information that all these detection systems provide, at the physical level, must forever remain separated and discrete. The laws of physics and information theory, both determined by the principles that govern physical existence, exclude the possibility that this information can be integrated into a single thing or phenomenon, like one's consciousness. If one's consciousness were a phenomenon of the physical, it would not be a single thing, but a collection of separate and discrete things. At the physical level, the unity of consciousness is an impossibility.]
The unique human volitional/intellectual/rational consciousness called the mind is an attribute only possible to a conscious living physical organism, and does not exist independently of the individual whose mind it is. Because it is an attribute of consciousness it has all the characteristics of consciousness: can only be known subjectively, is the same mind from the beginning to end of life, and is continuously and simultaneously conscious of everything there is to be conscious of.
Life, Consciousness, And Mind
Life, consciousness, and mind are not entities and not substances, but they exist in the same way velocity, color, or size exist, as attributes of physical entities. They are perfectly natural attributes, just like the mechanical and chemical attributes are, but they are not physical attributes, because they cannot be perceived, directly or indirectly, though life can be observed in its manifestation in living organisms and the evidence of the human mind is in every creation of the mind from the epistemological (language, mathematics, logic, science, history, geography, literature, art) to every artifact produced by human labor and technology, and no conscious being cannot not know they are conscious.
All the physical attributes are deterministic. The whole of physicalism (and the physical sciences) is based on the premise that physical existence has a specific nature which determines all physical behavior. It is that premise which the physicalists insist requires everything to be explained in terms of those physical attributes. It is very difficult to find fault with that view, especially in light of the success of the physical sciences.
I have a great deal of sympathy for that aspect of the physicalist view, but there is one aspect of it I regard as a denial of clear evidence that everything cannot be explained in terms of physical principles alone, and that evidence is the natures of life, consciousness, and especially the human mind.
It must be emphasized that the physicalist premise cannot be lightly dismissed and to question it requires something extraordinary. In the entire universe there is very little that would suggest there is anything wrong with the physicalist premise that everything can be understood in terms of physical principles. In fact, the only contrary evidence that is known is on this tiny planet earth and there is very little of that. It only exists in those rare entities called organisms, which even a physicalist must admit, relative to all other physical phenomena, are very unusual.
Materialism, Not Physicalism
By, "materialism," I mean the view that nature, or ontological existence, is all that exists and has the attributes it has independent of anyone's knowledge or awareness of that existence or its nature. It includes every physical existent, every organism, all conscious organisms, and all human beings, because they all exist and have the nature they have whether anyone knows they exist or what their nature is or not. (Of course a human being cannot exist without knowing it, but it is not necessary that anyone else does.)
Material existence and physical existence are identical with the exception that organisms have attributes in addition to physical attributes that differentiate them as organism. Those attributes are life, consciousness, and mind. Like the physical attribute, they are perfectly natural attributes. There is nothing mystical or supernatural about the attributes of life, consciousness, and mind, but that they are not physical attribute, they are attribute of a very small number of physical entities in addition to the physical attributes that make life, consciousness, and mind possible.
The "Mind-Body" Problem
There is a long-standing question in philosophy called the mind-body problem. The question is usually put in some such form as, "if the mind is not physical, how does one consciously control their physical body, but if the mind is physical, and therefore determined by the principles physics, how is choice possible?"
As explained, the mind is not a substance nor some incorporeal thing occupying a physical body, it is an attribute of the physical organism it is the mind of, an integral aspect of the organism without which the organism would not exist as the organism it is. It is the organism's life and consciousness, and, in the case of human beings, the mind that make it possible for the physical living organism to exist and act to maintain its own existence. Life, consciousness, and the mind are not separate in any way from human beings, they are, together with the physical attributes, what a human being is. The mind is not a separate thing that interacts with the physical, the mind is that aspect of the organism that makes it possible for that physical organism to know, think, and choose what it does. There could only be a "Mind-Body" problem it is assumed the mind is some separate thing from body, not an integrated aspect of the organism itself.
A Baseless Assumption
The physicalist assumes there can be nothing but physical properties, mostly out of an irrational assumption that to admit that reality includes possible attributes beyond the mere physical automatically assumes some form of mysticism or the supernatural. There is no basis for that assumption.
The fact that life exists and has the nature it has cannot be denied. It can, obviously, be denied that the existence of life cannot be explained entirely in terms of the physical attributes of existence [though it has not, and I'm certain, cannot be done]. What is certain is that whatever life, consciousness, and mind are, in this real world they are certainly possible (else they would not be) and whatever attributes of reality are required for there to be life, consciousness, and mind, they exist.
The virtue of the physicalist view is the absolute rejection of anything for which there is no observable evidence. The fault of the physicalist view is it failure to include all observable evidence.
Evidence Evaded By Physicalism
As important as it is to reject that for which there is no evidence, it is absolutely necessary to include everything for which there is evidence. Any evasion or dismissal of observable evidence necessarily means some aspect of reality will not be understood. Physicalists evade or ignore some very important observable aspects of reality. Some of the more important evidence dismissed by physicalists (or explained away when it cannot be evaded) include the following: the observable facts of life, consciousness, perception, volition, knowledge, reason, and, human interest.
The fact and nature of life—In addition to the nature of life described earlier for which there is no physical explanation, there is the fact there is life, an undeniable aspect of reality, for which there is no physical requirement. No non-living physical existence requires life. No physical principle depends on life. If there were no life, nothing of the physical world would be different (except for the artifacts created by living organisms). Unless life is as essential aspect of existence itself, there should not be any, because there is nothing known about any aspect of the physical that points to or suggests life.
The fact and nature of consciousness—Perhaps the most obvious evidence evaded by physicalists is consciousness. To be fair, when forced to, physicalists do not deny they are conscious, they attempt to explain it away as something that just emerges from the behavior of the neurological system or brain. But one's consciousness, however one has it, is not itself physical and has no physical properties and cannot be perceived. It can only be experienced by the one who's consciousness it is. To deny one's own consciousness is a flat-out rejection of observable evidence.
The fact and nature of perception—The physical is that which we are conscious of. Perception is conscious awareness of the physical. The simple fact is, conscious perception and what one consciously perceives cannot be the same thing.
When pressed physicalists will not deny there is direct perception of the physical, but do go to great lengths to deny that perception is reliable, which is strange, since the physicalist's entire thesis is that only what is perceived physical evidence is valid. If perception is not reliable, how can any science based on what is perceived be reliable?
If conscious perception of physical existence is not reliable, if what is perceived is not the real world exactly as it is, than all the science based on that perceived evidence of the physical is unreliable and all the physicalists certainty that physics explains everything is also unreliable.
The fact and nature of volition—The physicalist insists that everything is determined absolutely by the behavior of the physical which cannot behave in way not determined by physical laws. On that basis, they deny that volition is possible.
The denial, of course, assumes there are no other attributes of existence except physical attributes. But, as already explained, there is no basis for that assumption, and there is no conflict between the conscious aspects of living organisms and the physical aspects. It is the living, conscious attributes of an organism as manifest in the organisms behavior that make it possible for the life process to determine some aspects of the physical behavior of the organism. It is not one kind of thing determining another, it is one aspect of the same thing interacting with other aspects of the same thing—it is conscious choice interacting with the living organism that determines its behavior.
To deny that human beings are volitional is so obviously problematic, physicalists attempt to explain it by resorting to a distortion of physical science itself, such as appealing to the indeterminism of quantum physics. It is a very strange argument that actually denies their own premise that everything is determined by the physical.
The need to attempt to explain volition is understandable, because to deny it denies science itself, because it denies the possibility of both knowledge and reason.
The fact and nature of knowledge—If everything is determine by physical attributes only then everything that happens is merely a physical reaction with no more meaning than a dead tree falling in the woods. Knowledge assumes one is able to volitionally identify what one is conscious of, to discover what the nature of entities are, and discover what their nature is. If every event is nothing more than a physically determined event, no brain event has any meaning whatsoever, and cannot possibly be the identification or discovery of anything.
The fact and nature of reason—In the same way and for the same reason if all events are merely physical events reasoning is not possible. There is no possible way for mere physical events to make judgments or choices or to evaluate things. If there is any reason, any objective knowledge, any volitional choice, then there must be more than the mere physical.
The fact and nature of human interest—The physicalist believes the physicalist view is very important and will argue strongly for that view. It is difficult to see how the view could matter at all if it is true. If life, consciousness, and human minds are nothing more than elaborate manifestations of physical phenomena, how can they possibly matter and to whom. Do physical events matter to other physical events? If the physical is all there is, physical events are all there are, no matter how complex or elaborate they are.
Things do matter, however, even to physicalists, because a human life is more, much more, than a mere complex physical event. Every human being, including every physicalist is a living, conscious, volitional, intellectual, rational being, which cannot be explained only in terms of physical properties.
Just as all existents are whatever their attributes and qualities are, all physical entities are whatever their physical attributes are, but those attributes are not themselves physical entities or substances. Every physical entity has the physical attributes of size, shape, mass, and momentum. Another attribute associated with all physical entities is force. None of these attributes, however, are independent existents and only exist as attributes and characteristics of the physical entities.
There is no, "size," "shape," "mass," "momentum," or, "force," independent of entities. Of all these, force is the most interesting. "Force," only exists as a concept relative to acceleration. Acceleration is any change in any entity's motion, either a change in velocity or a change in direction, or both. A change in motion can be observed and the entities involved in that acceleration can be observed, but no, "force," can be observed. It is simply a concept for the relationship between entities that results in acceleration. The very formula for force, F = m a (Force equals the mass time the acceleration) illustrates that force is only a concept for observed behavior, not an entity or a substance. A strict physicalist ought to say, force does not exist, only entities which accelerate exist.
Once that is understood, it becomes obvious that mass also does not exist as either an entity or substance. Mass is also only a concept for a property of existents that cannot itself be observed, but is identified as a relationship between entities. There is no mass sans entities.
The insistence that everything be explained in terms of the physical is a gross superstition as mystical as any religion.