I wrote this as an example paper for a Philosophy class a few years back. It articulates a case for idealism.
Having examined the arguments for and against materialism, dualism, and idealism, I believe that idealism is the right answer. Dualism and materialism both lack evidence to support their claims, and they lead to absurdities when examined closely. Idealism is based squarely on the empirical evidence, and it leads to no absurdities (although it tends to rub our biases the wrong way).
Dualism is the position that most of our minds (at least in this culture) tend to gravitate towards as the default position. Perhaps part of it is that we tend to like anything that sounds middle-groundish; we are a culture that loathes anything that sounds extreme. Dualism posits that there are two fundamentally different substances in the universe--consciousness and mind-independent matter (let’s call the latter MIM from now on as a shorthand). I think there are some serious, unsolvable problems with this viewpoint. One problem with dualism is that we have no evidence whatsoever for the existence of MIM. All we ever actually perceive are collections of sensory qualities--touch, sound, taste, color, smell, etc. These are qualities that inherently assume minds that they are in. To conceive of texture, for instance, apart from a mind experiencing the sense of touch is impossible, because that experience makes up the very essence of the concept of texture. One may point out that of course we never observe anything but sensory qualities, since we have to observe things through our senses. Granted, but the point still remains. We never observe anything but sensory characteristics. We never observe MIM. So why believe in it? Some might argue MIM is necessary to explain our experience of sensory qualities. However, not only is MIM unnecessary to explain our experiences, it is impossible for MIM to explain them. Why? Because MIM cannot be the cause of our sensory impressions. If MIM exists, it is a substance utterly different from consciousness. Particles of MIM can, presumably, influence other particles of MIM, and you can have complex MIM objects made up of MIM particles. But MIM particles, being made of a fundamentally different substance from consciousness, would not be able to cause effects in consciousness, in the mind. If the mind is not a physical (in the MIM sense) thing, then how could physical forces affect it? Physical forces could influence physical objects, but a physical force could never influence a non-physical object. Nor could a non-physical force ever affect a physical object--only a physical force could do that. This seems self-evident from observing the very concepts of a physical object/force (in a MIM sense) and a non-physical object/force. So if these two substances exist, they could never interact with each other, which means that MIM could not be the cause of our sensory experiences. So our experiences give us no evidence for the existence of MIM at all. And not only is there no evidence for the existence of MIM, but since dualism requires that MIM and consciousness interact with each other in a coherent system, the impossibility of such interaction is itself another argument against dualism.
Another problem with the concept of MIM is that we really have no idea in our minds that corresponds to it. That is, when we talk about MIM, we have no idea what we are talking about. Take a table, for example. A table, as we experience it, is a collection of sensory qualities. According to the MIM theory, the reason I am observing the sensory qualities of a table is because there exists a mind-independent object, an object independent of anything that implies impressions on a mind, that is causing that image to be reflected onto my mind. But what would such an object be like? We must remove from the concept any characteristics that require the idea of a mind perceiving, which means we must remove from our idea of the object texture, sound, smell, color, shape, and taste. All of these sorts of characteristics imply a mind that is observing. Shape, for example, implies a particular viewpoint from which the shape is viewed, implying a mind viewing. All ideas of texture imply a particular experience of touch experienced by a mind. Once you separate all qualities that are connected to the mind perceiving/sensing, there is no idea left. Its very essence is gone. Now, it might be pointed out that of course this is the case, because since we are minds, we cannot imagine anything without tying it to our minds. Granted, but the point still remains. We have no real concept of anything apart from sensory characteristics. Sensory characteristics make up the very essence of our ideas of material objects. So when we talk about MIM objects, we really have no idea in our minds of what such a thing would be. Perhaps this wouldn’t be a big deal if we had evidence that such things existed--not knowing what something is like is not itself evidence that it does not exist--but in this case, we have no evidence that such things exist at all, as I have shown above.
Another problem with dualism is that the concept of two fundamentally different substances existing in the same universe/reality is absurd. We can imagine two physical objects existing in reality--say, a soccer ball and a tree--because they are the same sort of thing. They have physical characteristics, they can affect each other, they are in space in positions relative to each other (for example, the soccer ball might be 20 meters to the south of the tree). But what would it mean to have a physical object like a soccer ball existing in reality with a non-physical object like a mind? How would they relate to each other? Where would the mind be in relation to the soccer ball? How could the ball relate to another object in any other way than spatially? How could the non-physical mind, which is not a spatial object, relate to an object that is spatial in its nature? Trying to relate the two together would be trying to put together two mutually exclusive visions of what a “real object” is. It is like the metaphysical version of trying to run an old Apple computer program on an IBM. They aren’t compatible. And not only that, but if there are two fundamentally different substances in reality, they cannot have a common source. They would have to have independent sources. Not having a common source, they would be utterly independent and thus have nothing at all in common. They would not even share a common framework as parts of a larger reality. They would not share the same laws of logic or physics, etc. They could not be parts of a larger whole, which they would have to be in order to both exist in reality. So it is absurd to suppose that there is more than one fundamental substance in the universe. All of these arguments show that dualism is completely unviable as a view of the nature of the substance of the universe.
Materialism is another of the three possible views. It holds that there is only one fundamental substance in the universe, and that substance is MIM (mind-independent matter). It is obvious that many of the objections raised against dualism are going to apply against materialism as well. There is no evidence for the existence of MIM, we have no idea of what MIM would be, etc. Materialism appears on the surface to avoid the gap problems that dualism is prone to--that is, it seems to avoid the problem of trying to get two fundamentally different substances to relate to each other. However, I think it does have a very similar gap problem; it just gets to it by a different route. Materialists believe that consciousness is a product of the interaction of MIM particles. There is a universe full of mind-independent, non-conscious particles. When these particles interact in certain complex ways, materialists argue, consciousness is produced, mind is produced, with its thoughts, emotions, etc. The problems here is that if you arrange mind-independent, non-conscious particles together, what you get is a more complex mind-independent, non-conscious object. You don’t get consciousness. It doesn’t matter how many MIM particles you have or how complexly you arrange them together--no matter what you do with them, arranging MIM particles together will only produce a complex MIM object or system; it cannot produce something other than MIM, like mind/consciousness. If the particles are not mind, the object/system produced by their assembly will not be mind either, because nothing other than non-mind has been added to it. If the particles are not conscious, the object/system will be non-conscious as well, because nothing other than non-conscious matter has been introduced. All that changes is that now you have a complex system of mind-independent, non-conscious particles instead of a bunch of MIM particles floating about separately. Nothing in the whole thing is conscious, so the whole thing will be a non-conscious, mind-independent machine. As you can see, when you press it, materialism ends up turning into a kind of dualism. Instead of starting with two fundamentally different substances, like traditional dualism, materialism has a new substance created from an old one, which doesn’t solve old problems but instead creates new ones. The only way out of this would be for materialists to deny the existence of consciousness/mind. They could just say that there is nothing in the entire universe but non-conscious, mind-independent particles and the machines they create. But to deny the existence of consciousness would be to deny the existence of the only thing for which we actually have direct, observable evidence in order to preserve a belief in a substance for which we have no observable or inferential evidence whatsoever--which would be the height of absurdity. So materialism must be ruled out as a viable option as well.
Idealism is the only view that can explain the data of our experience. It alone avoids falling into the traps of the other two, and it creates no logical or observational problems of its own. Idealism says that consciousness is the only substance that exists in reality. It denies the existence of MIM. This fits the facts, because consciousness is all we observe to exist and have evidence for; MIM is a concept we have no idea of and no evidence for. Idealism has no gap problem like the other two views, because it alone (besides the version of materialism that denies the existence of consciousness) does not end up positing more than one fundamental substance.
There are a few objections that might be raised against idealism. One objection would be that it seems absurd to say that all objects in the world are collections of sensory qualities. Doesn’t it seem odd to say that when I eat an apple, I am eating an idea? When I walk across a room, I am walking across an idea? Well, yes, it sounds strange to put it that way. But we must remember that “idea” in idealism is broader than the way we use the word in causal conversation--it means not just some visual image I have in my head but includes all sensory perceptions, everything relating to touch, sound, sight, smell, and taste. When I eat an apple, the whole process never involves, as far as I can see, anything but a large and complex collection of sensory experiences. The same applies to walking across a room, or any other activity. Why do we eat in idealism? Because we are a small part of reality, and we grow by taking into us in various ways more of reality. We are interacting and growing in a very complex sensory environment in which there are many ways to interact and relate to things. But nothing that we do requires or implies the existence of anything other than sensory qualities. There is no logical problem here. The problem is that we are not used to thinking in terms of idealism and so the concept sounds weird to us. But “this sounds weird and is not what I thought” is not the same as “I have a rational argument against this.” We must learn to distinguish between these two things.
Another objection that might be raised against idealism is that it requires the concept of a universal mind in order to work. It is obvious that it is not only in my mind that things exist. The world has an existence independent of my association or causation. Therefore, idealists need to posit that there is a universal mind in which all sensory objects exist, and we sense things by means of participation in, or borrowing from (however you want to put it), this larger mind. An objector might argue that to posit such a being is an enormous leap and thus makes idealism suspect. There are two parts to the idealist response here: 1. If idealism has to make a leap here, what about materialism and dualism? They have to bring in MIM to make their systems work. We’ve seen that MIM is a substance which no one has any idea of, for which there is no evidence at all, and which brings with it a number of unsolvable absurdities. So if there is a problem here for idealism, it is certainly at least no less of a problem for materialism and dualism. 2. Is it a leap to bring in a universal mind? Even if it is a leap, is it as big a leap as bringing in MIM? That depends on what one thinks of the arguments for and against such a universal mind, and whether one thinks such a concept is logically tenable. This would bring us into theistic-atheistic arguments over the existence and nature of God, which we obviously do not have the time to delve into here. If God (what theists call a universal mind) is a logically problematic concept, then idealism has a serious problem here, but so do materialism and dualism; so they are all on the same level, they are all fundamentally flawed. If the concept of God is not logically problematic, but there is simply no evidence for such a being, then idealism has perhaps made a leap in bringing in God, but it is a logical and rationally acceptable leap. It is bringing in a concept that has no logical problems, which is a reasonable move, whereas materialism and dualism have to bring in a concept that is fraught with logical problems. But if the classic theistic arguments for God are good arguments (as I believe they are), then we have much independent reason to believe that there is a universal mind, and so bringing such an entity into the picture would not only be logically OK, but it would not even be making a leap at all. It would be bringing in something we already knew had to be there from other independent lines of evidence. So idealism would not be making a leap; rather, it would be providing another line of evidence for the existence of God, and it would be totally in accord with what we have already learned that the universe is like.
Another objection that might be made against idealism is that it denies the existence of material objects, which we can clearly see exist all around us. But, of course, this is just verbal confusion. Idealists do not deny the existence of material objects; they simply disagree with materialists and dualists about the nature of those objects. Idealists actually affirm the existence of material objects far more straightforwardly than do materialism and dualism. These latter views, in looking at a table, for example, have to say, “This sensory appearance of a table is not actually the table itself. The table itself is an object that exists apart from all texture, sound, color, shape, smell, and taste, an object that we have no idea of and no evidence for. That object (we know not where it is, since it is inherently unobservable) somehow creates the impression of a table on our minds (even though the impression, being made up of sensory qualities, is nothing like the original thing), by means of a physical force creating a non-physical effect, somehow.” An idealist looks at a table and says, “That collection of sensory qualities you actually see right in front of you, with its particular texture, color, etc.--that thing is itself the table. There is no unknown and unknowable object behind it that is the real table. We can actually observe the table itself.” Whose view does a simpler, more straightforward job of affirming the existence of the material objects we actually observe? Whose view avoids unsolvable complexities and simply affirms that which is self-evident?
I can think of no other objections against the idealist position. In light of all of the above, I conclude that materialism and dualism are false and that idealism is true.