The Problems of Philosophy by Bertrand Russell

I read The Problems of Philosophy over a century after it was published, and it's remarkable how well it has held up. A much more recent philosopher who is alive Daniel Dennett described philosophy in a TED Talk as making sense of what the sciences tell us. Russell himself described philosophy as concerning problems science hasn't yet answered or found a way to frame the question in a way it could be answered, and as a critical means of unifying the sciences. Philosophers still debate the nature of consciousness, free will, sense data, God, morality, Justice etc which the sciences still haven't taken over. The discovery that space and time don't always work the way we think we do was known to Russell back in 1912. The content is still relevant to philosophical problems today. 

The specific problems of philosophy are the difference between how we perceive the world and how it actually is (if there is a difference), the nature of physical objects and how we come to know them, the existence of universals like the kind we use in discourse, and the justification of truth. Absent are discussions of more "hot button" controversial issues like free will, God, ethics, or justice. Russell by his own admission follows in the tradition of modern philosophy since Rene Descartes and begins with doubt. Whatever cant be doubted should be the basis of philosophy if we are to find any certainty to our beliefs. This is a very different understanding of philosophy than the ancient Greeks or medieval thinkers had, and was inspired because of how wrong these old trusted authorities were about many things. This way of thinking precludes moral and metaphysical thinking until a basis for them is established, which is what Russell is trying to do here. It is critical for if there aren't things like universals as Russell thinks there are then universal morality and justice are in question. In Russell's time the certainty of the Newtonian worldview of classical physics was being undermined by the discovery of non-Euclidean space and the nature of light as a physical phenomenon, etc. Advances in logic, which Russell helped pioneer, made many philosophical questions capable of an answer or at least clarification. This of course became the "Analytic" school of philosophy which is dominant in English speaking countries. 

Russell can be described as an indirect realist. He acknowledges the difference between perception and reality, and that all we know if what we perceive, which is sense data. Yet he believes we can infer the independent existence of physical objects. Besides immediate sense data we have memories which gives us a sense of a past which is no longer. Next we alone among animals are aware of our own awareness, self-consciousness. We surmise that this thinking activity belongs to a self, which is the first relation to a universal concept we know. Our awareness of properties apart from instances implies something common with them. 

Yet Russell shares Hume's skeptical doubts regarding the "I think therefore I am"; that among our different thoughts there exists a self which is not located in any of these thoughts. So universals are relations between things, not an actual thing as it was for Plato. Universals have being, but not existence. For it to be true that Russia is north of Turkey, there must be truth to the relation north. The relation north is not mental or physical, it is just in mind, kind of like the self. This is the most confusing but I think crucial part of the book to establish Russell's indirect realism, and any realism I suppose. 

Idealists and phenomenalists argue that these relations are mental, either constituted by mind or not independent of the phenomena we're describing. Russell devotes a chapter refuting idealism by claiming it conflates having an idea of something in the mind as constituting the nature of that thing. As Berkeley argued, for something to exist it must be perceived by a mind, either our mind or the mind of someone else like God. Yet my having an idea of a tree doesn't really constitute its essence besides it being a thought of something. I don't get anymore information than that from just the having of an idea. As for phenomenalism I think he spends the whole book trying to argue not that it's wrong but that there is more than sense data. But his accordance with Humean doubts makes that difficult. Perhaps if he was a direct realist this wouldn't be as much a problem.  

An important distinction he makes is between knowledge by acquaintance and knowledge by description. It is possible for something to be true without our being familiar with it. It's true that Australia exists because others who are acquainted with the country can describe it to me in ways I'd understand if I had been there. This is like the criteria of replicability for experiments, under the same conditions the same conclusion should hold. Of course the phenomenalist would define this as the possibility of experience, not the knowledge of something without experience. This distinction relies on his acceptance of universals, more important than I realized.  

Russell holds what is called a correspondence theory of truth. All true statements refer to something beyond themselves, be it physical facts or universals. He has three requirements for truth: 1) truth has the opposite falsehood possible 2) truth is a property of beliefs 3) truth is related to outside things. The opposing theory of truth is called coherentism; the truth of a statement is relative to the truth of other statements. Something can be true in a circular way, coherent with one's background beliefs, and not refer to anything outside. Coherentism accepts the first two criteria of truth and denies the third. Russell claims that by relying on noncontradiction for coherence this view depends on the truth of logic being itself independent of statements. Again the importance of universals. 

The rest of the book from beginning to end is familiar ground for those with background knowledge of philosophy. He recommends Plato's Republic, Descartes' Meditations, Spinoza's Ethics, Leibniz's Monadology, Berkeley's Three Dialogues, Hume's Enquiry, and Kant's Prolegomena to any Future Metaphysics for beginners from which he draws from all heavily. 

What Russell gives in this short book are the important questions from the foundations of these author's arguments, minus the historical idiosyncrasies. Given the depth of Russell's work, this is a simple and very accessible book which does a good job of summarizing modern philosophy, even in the 21st century. I pretty much agree with it. 

The Universe as Energy

The world is fundamentally unconscious will which is divisible into what can be described by the physical concepts of matter and energy, which are the causal constructs imposed by consciousness on the metaphysical will.

The world is comparable to a continual transfer of electrical energy into mechanical energy and vice versa. The continual motion of mass via energy. The transfer of photons between electrons and the transfer between gravitational energy to kinetic energy between material bodies. Wavelength motion in mediums. Motion and attraction/repulsion between bodies. Enough energy for some reason was converted into rest mass so that space is filled with objects which light passes through, taking different forms in these processes which result from the motion of light energy through mediums (heat, color) and governing interactions between the objects in space exchanging electrical charge (electromagnetic force). 

Space and time, as distinct from our perception of them, are physical things which are affected by energy. What we call space is just another feature of the gravitational field of the universe; space-time does not exist apart from the matter and energy that creates the gravitational field. Energy is convertible into mass, e=mc^2. Energy and mass warp the fabric of the phenomena of space-time. 

It is the existence of matter that allows us to see light in a visible form, both as an object and as a subject. 

A world of pure light would be blinding and incomprehensible. Light become matter so that we could comprehend it, so to speak. A world of pure space would be dark and indistinct, without light. The existence of material objects gives us the contrast of the light and dark, light and "empty" space. Pure light and pure dark have no color, just as when one looks directly into the sun or into space. It is the sky around the sun and the planets in space which have color.  It is the interaction of energy with mass and space-time which constitute the world we inhabit.

In light we can understand how the different things can be fundamentally the same, such as mind and body. Light has aspects of both particle and wave; a field of force and a particle. Our vision is due to the mechanical movement of the retina and the transfer to electrical energy via the optical nerve to the brain. In a medium light travels at different wavelengths, which seems to slow down the speed of light. However the speed of light is finite, even in a vaccuum. Light still travels faster than anything else in a medium, so the the law of causality still holds for other phenomena. This is how people can see different colors, while the wavelengths of light being the same.

Light is our awareness of the world, our personal connection to the universal energy. Light is the free energy not bound to do work by its nature. After exchanging energy with objects, light travels at its speed as a massless particle. Thought processes are synonymous with the nervous system which is comparable to a system of electric signals. Mind's qualities of simultaneity and instantaneity of events as compared with matter is like the activity of an electromagnetic field. Electromagnetic processes occur at the speed of light, a transfer of energy from one particle to another. The speed of light is the speed of causality because it occurs faster than anything else as it is in itself free of causality. Light travels faster than anything else because light has no rest mass, meaning that there is no energy to overcome to accelerate. At the speed of light all there is no distance between events, there is no before and after, only the present. 

It is everything else, including our bodies, which have rest mass which fall under causality. Since force equals the product of mass and acceleration, F=MA, with no rest mass the speed acceleration is as great as the energy gained by motion. As E=Mc^2, light is pure energy free of individuation within space and time since light has no rest mass to overcome its acceleration. 

The existence of rest mass, our body, is the physical analogue to desire as the source of suffering. Because of rest mass we don't live in the present. We can imagine different states of affairs, but not always act in accordance with them. We have to choose among alternatives presented and not created by us. We form expectations about the future and fixations about the past which do not reflect the present. In animals and indeed for most humans in most of their history little energy was free to speculate on the different possibilities. Thus for us the idea is different than reality, creating duality and opposition between things. But living things are dynamic, constant energy converting machines. The meaning of the idea is only in the transient individual forms. The objects of consciousness define the meaning of existence. Individuality and suffering are bound into the nature of conscious existence. 

A Poem: The Illusion of History.

One is not unhappy if their natural history of creation is untold
To open the past is to forget the present
Three days was all it took to undo history
For life is the book unwritten
Five years the same as five millennia

The Mystery of the Universe: The Relation of Subject and Object

"Throughout nature, as presented to the senses, everything depends on the relation which things bear to each other, but especially on the relation to which man, the most important of these, bears to the rest. Hence the world divides itself into two parts, and the human being as subject, stands opposed to the object. Thus the practical man exhausts himself in the accumulation of facts, the thinker in speculation; each being called upon to sustain a conflict which admits of no peace and no decision."
-Johann von Goethe Theory of Colors

The great mystery of the world is why reality is divided into knower and the known, where both are in a relationship but the knower knows itself more than the known. From this we can proceed no further.


Arithmetic comes to us via the perception of time, of a succession between moments. The inner experience of time is the most basic cognition, which is a one dimensional succession of experiences. The beating of our heart, the expansion of our lungs, the most vital involuntary bodily processes are the origin of our a priori sense of time. From time comes our knowledge of arithmetic, the rules governing numbers which succeed one another in an ordered fashion. Arithmetic follows the rules of discrete succession, whereas music, which seems to be the most immediate form of art, follows rules of relative succession, to our aesthetic senses.

The pleasing sound of our familiar parent's voices, and the sound of their beating hearts when they hold us, being so immediate could make music like arithmetic and time so primary. Our sense of sound is more developed than our sense of sight when born.

Geometry is known to us via spatial perception of several dimensions together. Outer experience of space requires several dimensions, experiences occurring in different successions. Memory brings this plurality of experience together. Beginning with the contraction and relaxation of muscles the effects of past experiences exist with current more intense sensations. Contraction is potential energy and relaxation is kinetic energy. The effects of the build up and release of energy remain in the body for some time and can lead to mechanical change, muscle memory. The notion of spatial extension comes from the possibility of continual experience, inferred from past experience (time). The notion of infinite space is the possibility of taking one step further. The knowledge of geometry comes from spatial perception, giving mutual relationships for different successions between points. Geometry is the static application of rules to successive dimensions. Physics, the most ancient of which seems to be astronomy, is the study of objects in motion in spatial dimensions.

Causality is a synthesis of both space and time, which is systematized into science, the body of knowledge. A preceded B in time in this space, and B succeeds A in this space at a different time, so A caused B.

That the a priori is an actual part of the world of experience, though a very selective part, is demonstrated by the fact that there are non-Euclidean geometries which does not assume space is flat and only three dimensional. The shortest distance between two points in curved space is a geodesic! A curve, not a straight line. Kant died before these discoveries, first made by the Russian Lobachevsky in the 19th century. In this geometry Euclid's synthetic fifth postulate, that between a line and a point not on the line there is one parallel line which does not intersect, is not a priori. The two parallel lines intersect in curved space.



The more we explore the interconnection between the a priori and the world, the more we see it as an an aspect of the world of perceptual experience. Phenomena is a part of the world just as objects, noumena, are. The a priori is part of the world of experience itself, it follows the same rules as objects.

Eclipse of Reason by Max Horkheimer

I decided to read Horkheimer because of his interest in Arthur Schopenhauer, a philosopher usually not dear to those in the Marxist tradition given his intense personal hatred of Hegel and the association with Nietzsche and the Nazis. His metaphysical pessimism seems to go against the gospel of the inevitable triumph of the workers and the possibility of an end to human misery in the communist society.

But Horkheimer and other western Marxists, especially in the Frankfurt School which he was a founder of, were willing to explore the boundaries of Marxist theory. They were puzzled as to why the working class didn't revolt after World War I. Why didn't the Bolshevik Revolution spread to Western Europe and succeed?

Marxism was considered a scientific theory in the level of Darwin's by its followers, with the triumph of socialism an inevitable result of the laws of nature. Marx thought the Western European nations like British and France were where capitalism had developed to a point where the working class was large enough and self-conscious in urban society to challenge the bourgeoisie. Lenin and others who thought a undeveloped nation like Russia could establish socialism, the revolution would eventually succeed on an international level. Otherwise Russia would be isolated on all sides by hostile powers.

What instead happened was fascism. It could be argued that the ideological wave inspired by the Bolshevik Revolution was fascism, which swept over Europe from the 1920s until after World War II. In an economically advanced and educated Germany came a fanatical regime which in the course of twelve years tried its best to transform the entire world order.

This forced in the west a reexamination of the fundamentals of Marxist theory, from its philosophical foundations. The question of Eclipse of Reason is how in the post-enlightenment west could people be so blind to their interests under capitalism and rationalize the irrational brutality of fascism?

Horkheimer argues that what the Nazis did, barbaric as it was, was nonetheless guided by rationality. The regime used brutal technological efficiency to control and exterminate millions of people.

Approaching the book one must understand that common discourse aside, there are different kinds of rationality, which is the only way to understand how the Nazis could be called rational. Horkheimer argues that this kind of rationality has pervaded western thinking, as not only a German or class phenomenon.

Horkheimer present three kinds of reason: objective, subjective, and instrumental.

Objective reason deals with ends, determining actions by how reasonable their purpose is. Objective reason sees facts as leading to ethical ends, is determining ought. This is the reason used by Plato and Aristotle. Objective reason is connected with religion which has ethical and explanatory dimensions. Philosophy emerges which critiques religion, hoping to replace superstition and prejudice with reason. Horkheimer identified German idealism within this tradition, as against those who accuse the tradition of inspiring relativism.

Subjective reason determines the rationality of ends by the means available. Something is rational if it gets me what I want, even if what I want is immoral or against my actual interests. This kind of reason emerges in the modern era with Machiavelli and Hobbes and is linked towards the hard sciences, which are true without regard to human purposes and morality. Subjective reason separates is and ought, fact and value. The only "universal" value of subjective reason is self-preservation. Subjective reason coincides with the rise of capitalism and individualism, with the breakdown of traditional modes of being.

Instrumental reason is a formalization of subjective reason which dispenses with ends altogether, instead adopting the criterion of usefulness of meaningfulness. If ends cannot be defined from means, they are useless and meaningless. Pragmatism and positivism are representatives of instrumental reason, wanting to emulate the sciences in the experimental method (pragmatism), logical rigor (positivism) and in eliminating metaphysics. Instrumental reason's goal is the unification of reason, the elimination of ordinary folk language, and value free knowledge. This is the product of late capitalism when the individual is subsumed to new technological social organization. As opposed to subjective reason, not all aims are equal. The very notion of the subject and introspection is not formalizable and so useless and meaningless. This kind of reason eliminates the individual for the furtherance of the social system.

Horkheimer prefers objective reason out of the three because it doesn't just seek domination of nature, but also understanding. There is some kind of moral grounding for our actions, a healthy criticism of our ends, and resistance to certainty. Subjective and instrumental reason in contrast see reality foreign and even dangerous in so far as they are out of our control. Sir Francis Bacon's dictum "knowledge is power" is the essence of instrumental reason. Knowledge also becomes a tool of social domination, as human nature becomes demystified and unified with the rest of nature as an object to be controlled.

Fascism is rational in the instrumental sense. Their ideologies of the race and nation are vague and mythological, but the means towards these ends become ends in themselves. Humans, seeking collective fulfillment in the nation, a race, or leader, become objects of domination. Their needs become something in of themselves, reaching toward nothing more than gratification, by means of control. Fascism imposed order on capitalism which was facing serious challenges by suppressing dissidents in the population, defending the social order at all costs, subordinating reason to will.

Horkheimer explores the psychology behind fascism through mimicry. We aim to control nature by becoming like it. We find freedom through blind brute force. Unfortunately nature is out of control and will destroy us if we do not act in our interests.

Unfortunately for conservatives we can't just go back to older forms of objective reason like Thomism. A critical point of Horkheimer is that ideas are rooted in culture and society. Subjective and instrumental reason rise with the capitalist society. Thomism was made to reconcile Christian doctrine with Aristotle, one of the few authorities available on science. In today's world of quantum physics, Thomism is of no help. Today's secularized and individualized world has little need for scrutiny of arcane Christian dogma.

The best chapter of the book is The Rise and Decline of the Individual. Here he defines individuality in historical consciousness, not just spatial temporal and sensual existence. The development of the self is determined by external factors, which we must gain knowledge of to be free and not have our identity be determined from without. The western individual Horkheimer says comes from Greek tragedy. "The tragic hero originates in the conflict between the tribe and its members, a conflict in which the individual is always defeated." The individual is defined by its conflict with external forces and circumstances to eliminate that division is to eliminate the individual. Resistance to irrationality is the core of true individuality. Formalized reason eliminates irrationality by control of nature, and in the process comes to eliminate the individual.

The resistance to instrumental reason can only come from a philosophy devoted to criticism from outside the inner rationality of the system, using philosophical dialectics. Horkheimer however rejects the higher synthesis that Marx and Hegel's dialectic offered, the end point of human social development which resolves the fundamental contradiction between the individual and society. There is no teleology to history as consciousness is developed under historical conditions for certain needs. There isn't an end point for philosophy; what philosophers and intellectuals should do is to highlight those who struggled against formalization and push history forward. History and the positive data of science is a record domination to be criticized. Ideology is always aimed at some kind of control, an overcoming of difference by denying to consciousness certain aspects of reality. This totally undermines objective reason and the German idealist tradition he looks favorably on and creates a new kind of reasoning: critical theory.

Critical theory treats ideas as inherently social and therefore political. There is no distinction between fact or value and in keeping with Marx the dominant ideas of society are impositions of the ruling class. In the hands of critical theory however the ruling base of society is cultural as well as economic. Race and gender as well as class are sources of oppression and so reason ignoring such realities accepts the status quo. There isn't as in classical Marxism an objective reason for inequality, which makes critical theory purely negative and disdainful of science. In essence, what has become known as political correctness.

To forward Marxism, one has to relentlessly criticize western culture which gave rise to capitalism but also to objective reason which Horkheimer and the Frankfurt school undermined. This for me seriously undermines Horkheimer's own critique of instrumental reason, which now seems like a demand for science to be in service of political correctness, as defined by the Marxists.

This is the first time I read Horkheimer or any of the Frankfurt School directly, and I can already see how pessimistic their worldview is. Which is where I suspect where Horkheimer's interest in Schopenhauer came from. The rest of the school were heavily influenced by Sigmund Freud and inherited Schopenhauer's pessimism that way.

Unfortunately in the hands of Marxists, such pessimism turns into defeatism and the regressive ideology of political correctness aka cultural Marxism which the Frankfurt school helped found. If one does not believe in such a thing as a human nature or transcendent moral truth, the world becomes completely intolerable, science politicized, and any weakness is to be obsessed over and any greatness condemned. Marxists should have been pessimistic since World War I seeing how their ideas failed over the 20th century, but should have realized the fault is socialism itself and not western civilization.

Despite the awfulness of the ideas Horkheimer's work helped found, the book is not bad. Given the unintellectual nature of the cultural Marxists today, this book is of interest for conservatives to find out where western thought went wrong, for the fascists and the Marxists.

Supervenience Phenomenalism

Supervenience phenomenalism; all facts about the universe are actual or possible sense experience. Two worlds which are the same in sensory facts are the same in physical facts. There are not two universes in which physical facts are the same and sense facts are not the same.

Phenomenalism is the philosophy that facts about physical objects are dependent upon or are entirely explainable in facts about actual and possible sensory experiences. Supervenience is a relationship where no two things can differ in their fundamental properties without also differing in their different respective properties. The biological supervenes on the physical and the chemical in that changes in the physical and chemical mean a change in the biological, but not the other way around. This doesn't mean all things like social groups can be reduced to fundamental particles, as there are multiple and higher levels of properties. But sense data is the most fundamental kind of thing there is which everything else depends on. The mental and the physical supervene on sense experience. A change in sense data means a change in the physical and the mental

Phenomenalism is committed to a third type of thing in the universe, sense data, which can be distinguished from mental and physical phenomena by their 1) subjective content and 2) being externally caused. Sense data is mind independent and physical in the causal sense, but not physical and mental in its subjective nature, existing independently of physical objects said to cause them. Sense data is always known to a mind, but mind doesn't constitute them; they constitute mind and anything that is thought about. Sense data is the fundamental basis for both mental and physical properties.

Critics can use a similar argument used against Platonic forms. That is that sense data is redundant, as it only explains the mental and the physical by being self existing. But applying Occam's razor and eliminating sense data would not make the explanation of mind better than the physicalist position. Mind would remain hard to explain given contemporary physicalist approaches such as eliminativism, identity physicalism, behaviorism, and functionalism.

There are reasons to assent to the belief in sense data as the single ontological substance. The most relevant reason to philosophy of mind is that it answers the hard problem of consciousness, accounting for qualia. As a neutral monist philosophy, the relation of body and mind is answered. Phenomenalism is also completely compatible with the conclusions of science, which are revisable in the face of experience. It is my opinion that phenomenalism provides us all the benefits of physicalism while giving a satisfying account for subjective experience and the relationship of mind and body.

The major objection to phenomenalism is an objection to translational phenomenalism, now considered untenable. According to translational phenomenalism, claims about physical objects share the same meaning as a claim about actual or possible sense experience. There is not a physical fact that cannot be translated into a sensory experience fact. The claim that there exists a table so that the claim there is a table in this room is true can be translated as if one were to extend their hand in front of them, they would feel the hard surface of what we call a table. There exists a tactile sensation of the skin so that there is a table in the room is true.

The problem with this kind of argument is that no purely sensory claim is necessary for any given claim that a physical object exists. If the sensation can be realized in different ways, by illusion or hallucination, then the sense experience said to correspond to a physical claim is not necessary. If I try to convince someone who is blind there is a Lego brick in front of them, I could say that if you keep walking, you will feel pain in your foot (assume they're barefoot). But the blind individual could feel pain if there were other things there, or even be in pain if there wasn't anything on the floor (perhaps by my suggestion).

This criticism is widely considered to have defeated phenomenalism. Physicalism however was able to survive similar objections decades ago by adopting supervenience. Identity physicalism was criticized on the similar grounds of multiple realizability, that a mental experience can be caused by different physical events. It is practically impossible to demonstrate a physical event for each mental event. Functionalism was proposed to remedy this; mind is a causal relationship between material things. Mind is defined by what it does, as Steven Pinker puts it, "the mind is what the brain does." Functionalism is an epistemology; the related ontology is supervenience. Supervenience is a one way dependency on one state of objects on another. Mind only exists if matter exists, but matter exists if mind doesn't exist. Mind is then a level of material functioning which depends on more fundamental material function, at the biochemical level.

Causal relations however are not necessary relations. We establish the relation between activity of the brain and thought by inference, not by fact. The mind is associated with what the brain does. Per Hume, there is no necessary connection among different things. No amount of experience can demonstrate that one thing always follows another, if they are different. Bringing in Leibniz's law, the Identity of Indiscernibles, what can be said about mind cannot all be said about the physical body. Here I invoke such properties from three arguments; disembodied existence, divisibility, and introspection. 

Disembodied Existence:
1. My mind can exist separate from anything physical.
2. No physical part of me can exist separate from anything physical.
3. Therefore, by Leibniz's Law, my mind isn't a physical part of me.

Divisibility
1. My physical parts are divisible.
2. My mind is not divisible.
3. So my mind is distinct from any of my physical parts (by Leibniz's Law).

Introspection
1. I can come to know about my mind (mental states) by introspection.
2. I cannot come to know about my brain (or any physical states) by introspection.
3. Therefore, my mind and my physical parts are distinct (by Leibniz's Law).

There is no necessary relationship between different things. If the mental and the physical are different in kind, then their relation is inferential, and more reliant on induction. If two things are different, we have no idea in the mind of their connection for if there is something there, it belong either to one of them or to something else. Only by a number of different experiences, more than one at least, can we infer a causal relationship. But this then depends on induction which does not operate on necessity, as we can imagine that there is no causal relationship at all without being in contradiction.

Since mental properties differ from physical properties, if we want to assert some causal or ontological relation, we must assent to the existence of a third class of objects which is not predicated of anything else, as it is capable of explaining the properties of mind and body.

Physical objects are a class of sense experience. Subjective experiences, the mental, is known to us more intimately via introspection and can be considered a lower class of ontological functioning which can exist without corresponding physical objects, isn't conceivable in spatial temporal extension, and is of more direct knowledge.

An epistemological alternative to phenomenalism is indirect realism. Indirect realism, representational realism or causal realism stands between strict physicalism which is realist about the existence of mind-independent physical objects and phenomenalism which acknowledges properties which are subjective and together with physical properties make up the world. Indirect realists agree that qualia exists and our perception of objects does not always correspond with their true nature, but think that qualia is caused or is explainable by the interaction of external objects on mind. The position is compatible with non-reductionist versions of physicalism as physicalism is ontological and indirect realism is epistemological.

Indirect realism faces a similar problem as physicalism does ontologically. How does one infer the existence of a whole class of objects when one only has access to perceptual experience? This is a vertical inference rather than a horizontal inference. Phenomenalism makes horizontal inferences about objects and their relations; from one sense experience to another sense experience.

The causal realist account since Descartes is that since we can infer our own existence, why can't we infer the existence of other entities like we did with ourselves? Incidentally this is also at the foundation of idealism, though with only minds of others and God as objective. I think and there are thoughts, so must I exist to have them? But all we actually have are thoughts, many of which are not causally ascribable to the self. Thoughts can exist whether or not we think them. And there is no particular thought which the self can be located. Like can only come from like, idea from idea. So it is not necessary to explain the effects we have, ideas, by anything greater than ideas.

The nature of objects is known by abstraction, which is really separating certain qualities of something which are able to exist on their own. We can imagine a horse which has lost a leg to still be a horse for example. But our prior notion of a horse is itself a collection of properties, which at a certain point enough satisfy our notion of what a horse is. Even if we were born with an idea of a horse, it would still be an idea in the mind which would not guarantee the objective existence of such a creature, much as we are able to imagine unicorns or the god Cthulhu. We are always abstracting with what we already know, to try to discern a common relationship with similar phenomena.

Indirect realists assume a distinction between properties which actually belong to an object and those which are only perceptual and caused by objects; primary and secondary qualities. Spatial qualities are supposed to be primary qualities, and the phenomena of color and sound are secondary. The real distinction however is that primary qualities are a priori features of the mind, prior to individual experience, which are imposed on objects of perception by the nature of individual consciousness. There is an intellectual nature to perception, besides its intuitive, non-reflective nature. We can only intellectually comprehend reality in certain ways. For we conceive of reality as having three dimensions but the math of physics tells us that there could be many other spatial dimensions. We can infer those dimensions insofar as they are instrumental towards understanding the universe, affecting what we do perceive. There is no reason to assume the a priori way we understand things apply to the universe itself. All we have of the universe is sense experience, particularly in astronomy where most of the data is from wavelengths of the light spectrum. We shouldn't hold some our intellectual notions above what the data tells us.

Supervenience phenomenalism doesn't have the difficulty of inferring a class of objects different and independent of what we experience. The real problem of knowledge is that we try to reason more than is necessary. Supervenience phenomenalism passes two critical tests: Occam's razor and compatibility with science. It is more simple but not too simple when it comes to explaining the mental and the physical, and avoids reifying scientific concepts into comfortable anthropomorphisms.

A potentially disappointing consequence of supervenience phenomenalism is that much of what people consider mind or non physical can actually be explained physically since all of what physicalism says still holds. The only thing not explainable by the physical are subjective mental images, not any sorts of composite objective entities. The soul, God, the afterlife, ghosts only exist as subjective sense data or physical facts. If neither of those, then there is nothing in of themselves which can be said to be true or false. Mind and body are not truly distinct things, but different aspects abstracted from the sort of thing.

Verificationism

Verification independent statements cannot be known to be either true or false.

There is no matter of fact as to P or not-P (which is the law of the excluded middle).

Only the law of non-contradiction holds for truth and falsity, not the law of bivalence. Not everything before us can be known to be strictly true or false in terms of propositions, only that something can't be both true and false. Something can have indeterminate meaning to us if it is not a matter of fact, verifiable by experience.

The law of the excluded middle is a tautology without regard to matters of fact. It always holds to be true no matter the truth of the terms. The alternative of not-A to A can mean anything. Both claims A or not-A cannot be both false; this doesn't make them true either.

Tautologies don't refer to anything that actually exists. That A is A (identity) and not-B (non-contradiction) is true, but that A is either A or not A doesn't mean anything in terms of true or false propositions. Much like when someone says they'll either do it or they don't. That doesn't mean anything even though it's not contradictory.

Non-contradiction does not prove that something exists as a matter of fact. Whatever exists as a matter of fact cannot be denied, but as to something which cannot be verified, the only way to prove this something a priori is if its opposite implies a contradiction. If something implies a contradiction, then it is inconceivable. But everything factual can be conceived not to exist. Therefore nothing can be proved to exist as a matter of fact prior to experience.

"… there is an evident absurdity in pretending to demonstrate a matter of fact, or to prove it by arguments a priori. Nothing is demonstrable, unless the contrary is a contradiction. Nothing, that is directly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no Being whose contradiction is demonstrable." David Hume, Dialogues Concerning Natural Religion

This makes necessary truths, which are always true, not meaningful to anything outside of the concept. The laws of nature, for example Newton's second law force equals mass times acceleration F=ma, are true according to the phenomena they describe. As exceptions appear, such as the impossibility of accelerating matter faster than the speed of light, the law remains true for what it describes, but more and more isn't able to give us any new knowledge or answer questions. Thus a completely necessary truth is tautologous, insofar as it is devoid of synthetic claims, describing its own terms and not anything else. They hold for any possible combination of facts.

"When someone hides something behind a bush and looks for it again in the same place and finds it there as well, there is not much to praise in such seeking and finding. Yet this is how matters stand regarding seeking and finding "truth" within the realm of reason." Nietzsche, On Truth and Lie

In some cases we may not be able to prove P nor prove not-P. To say that it must be one or the other doesn't tell us anything.

The truths of conjunction and disjunction are not denied. Conjunctive propositions are only true if both terms are true. The truth or falsity of one does not determine the truth or falsity of the other. If A is true then B can be false, making the statement false. Only if A and B are both true is the statement true.

Disjunctive propositions can be false, if both terms are false. If either A is true or B is true, then the proposition is true. A or B is true if we can prove A or B. But we cannot prove A or not A is true because we may not be able to prove A or prove not-A. If it isn't possible to prove a statement, then it isn't true or false.

Being independent of verification does not necessarily make something not true or meaningful. What is verified can be true independent of the act of verification, but can only be known to exist if verified.

This opens us up to mysticism suggested at the end of Wittgenstein's Tractatus, comaparable to Freud's Oceanic Feeling and Schopenhauer's platonic forms
.
6.44 Not how the world is, is the mystical,but that it is.
6.45 The contemplation of the world sub species aeterni is its contemplation as a limited whole.
The feeling of the world as a limited whole is the mystical feeling.