This phrase is often used to describe my basic philosophical outlook, though I don't use it myself. (I refer to my view as "immaterialism.") Basically, idealism, in its purest form, is the view that only minds and the contents of minds exist—i.e., that matter is an illusion.
So why is my idealism said also to be "subjective"? Well, the real reason may be that philosophers are uncomfortable with any term that is insufficiently polysyllabic (how's that for a philosophical phrase?). But the official reason is to differentiate my view from other versions of idealism.
I talk about things existing only as relative to a particular, individual mind; that's subjective idealism. "Transcendental idealism," by contrast, explores reality as relative to the mind in general, or the mind as such. That's the view of dudes like Kant and Fichte. Then there's Hegel's "absolute idealism," which begins within the mind but ends up attempting to grasp all of reality in its entirety. There are other versions of idealism, too, but you get the idea.
It's a little hard for me to give a precise definition of this term, since I claim it doesn't exist. But I know the kind of thing people seem to have in mind when they talk about "matter." I also know that, in the end, they really don't know what they mean. It's my job to show them that fact—over and over and over and over. Sigh.
But, yeah, what people typically mean when they speak of "matter" is an alleged mind-independent, unthinking, extended stuff that makes up most or all of the world around us. This stuff is also held to be the cause of the vast majority of sensations and/or ideas in our heads.
My view is that matter is an illusion.
For me, an idea is simply an immediate object of the understanding—it's whatever we are directly aware of. If I say to you, "Quick, don't think of an elephant," the elephant that inevitably comes to your mind is what I mean by "idea."
Fine, you say. So what? Well, whenever we use our sense perception, we are always in direct contact with what we are sensing. Sensible things, in other words, are what we immediately perceive.
But wait a minute. If a sensible thing is what we immediately perceive, and if whatever we immediately perceive is an idea, that means… all sensible things are ideas. Right now, I'm seeing a desk in front of me, fingers typing away on a keyboard. Are these just ideas?
You got it! This desk, those fingers, the tree in your yard, that angry person lumbering over here who just realized I snagged the last two doughnuts—all ideas. The whole world of so-called "material objects" is, in fact, nothing but a huge collection of ideas!
Okay, so you just read my two cents on the notion of an idea. And now you are probably going to try to get really slick with me: "Oh, so you're saying everything is an idea, eh? If everything is an idea, then the word 'idea' doesn't mean anything anymore." You think you've got me, don't you?
Sorry, chief, but I'm miles ahead of you. I never said that everything was an idea. No: while it's true that reality contains no material objects, there are also what I call "spirits" (sometimes I also call them "minds"). Spirits and ideas are the two kinds of things that exist. And that includes God, by the way: the supreme being is a kind of spirit—an infinite one.
So, what is a spirit? A spirit is an active faculty that contains our ideas (basically, it's a mind). When you have understanding and will, then you have a spirit. Ideas, by contrast, are inactive, and they are incapable of existing on their own.
The point is that you have to draw a sharp distinction between a mind and its contents. Descartes had a good head on his shoulders and made some important advances, but this was the one key point that guy could never see. The mind or spirit is the conceiver, while its contents (thoughts) are the conceived.
Suppose, for example, that I say, "I see a tree." "Tree" here refers to an idea, while "I" refers to a spirit. The tree is what is perceived, and, as such, it cannot exist on its own. The "I," on the other hand, can exist on its own—a spirit doesn't belong to anything else, and it's not a property of anything else—and the "I" is that which is doing the perceiving.
These are the two characters in my Three Dialogues. "Hylas" is derived from hyle, the Greek word for "matter." "Philonous" in Greek literally means "lover of mind."
And now a very tough question for you Shmoopers: Can you figure out which of these characters represents my own point of view? Take your time.
I didn't come up with these terms myself—the distinction has been around for a while in philosophy, but it's especially clearly drawn by my man John Locke. And if it comes from Locke, and it's not the basic doctrine of empiricism, you can be pretty sure I'm going to be opposed to it. What can I say? I have a conflicted relationship with my mentor.
This is a distinction between those properties (the primary qualities) that are thought to belong to objects in themselves, and those (the secondary) that are a function of the observer.
Take this chair, for example. Locke took the standard position that properties such as extension (the way the chair takes up space), size, shape, and motion are all objectively part of the chair itself. But qualities like the color of the chair, its smell, and its taste (we'll take Locke's word on this one) are actually not part of the chair itself; these qualities result from this object's effect on our particular sensory organs.
Well, that distinction may seem fine to others, but I showed that it is more garbled than John Travolta's pronunciation of "Idina Menzel." After all, the size of an object varies in accordance with the nature of the observer, every bit as much as its color does. A pencil may look small to us, but it will appear huge to a mosquito. Likewise, shapes appear different from different perspectives. All this is to say that supposedly "objective" primary qualities are as mind-dependent as "subjective" secondary qualities.
But I bet you already see the larger point of my argument (don't disappoint me now). It all goes back to my overarching idea that nothing whatsoever has any existence apart from a mind. As I always say, you can't be afraid to repeat yourself. Also, you can't be afraid to repeat yourself.
Admit it—when you first heard my claim that material objects don't exist, you thought I was some kind of crazy skeptic, didn't you? I get that all the time. And you know what? It's really tiresome.
So listen up world: I am not a skeptic. A skeptic is someone who denies the existence of sensible things, or at least says we can't know anything about them. So, tell me, is that my view? Is it? (Hint: it isn't.)
Certainly, I deny the existence of material objects, because, as I show, the existence of "matter" makes no sense. But I do not deny the existence of a world of external things. Not for a moment. I just point out that their real nature is immaterial, rather than material.
That's why, far from being a skeptic, I am actually a philosopher of common sense. Yes, you heard me right: common sense. The commonsensical view is the one that says that a world of external things exists and that those things are, in reality, pretty much the way our senses perceive them. And that is exactly my view.
It takes me many books and lots of high-flown arguments to arrive at the position of the man in the street. But, in the end, I get there.
I am critical of this notion, yes, but I don't reject it altogether. That would be a pretty silly thing for any philosopher to do, given that abstraction is our conceptual bread and butter. Instead, what I criticize is only a certain way that philosophers have attempted to make sense of abstraction—in particular the notion of an abstract idea.
Now, lots of philosophers have appealed to abstract ideas in one way or another. But I focus my attacks on—who else?—my empiricist brother, John Locke. I told you I have a conflicted relationship with him.
Locke says that we need abstract or general ideas in order to be able to communicate effectively with one another. Since all ideas are gained through experience, and since everything we experience is particular, he says that abstract ideas are arrived at through a process of reflection. His claim, then, is that in our minds we come up with an abstract idea of, say, a dog or a triangle in order to be able to talk about a dog or a triangle in general.
The dude's right that we need to use abstract terms to communicate. But come on—does anyone actually have an idea of a dog in general in his or her head—a dog that is indeterminate in size, color, shape, and so forth? I know I can't arrive at such an idea.
The more you think about this theory, the worse it seems. Take the notion of a triangle. In order to have an abstract idea of a triangle in Locke's sense, we would have to have in mind a figure that is equilateral, scalene, and isosceles all at the same time. That's not just a little hard to imagine—it's impossible, since it's a total contradiction. It's almost like trying to imagine Dick Van Dyke as actually being Cockney in Mary Poppins.
I have a much more plausible way of making sense of generality. I claim that all our ideas are particular, but we can still sometimes use them to denote something abstract. So, for example, if a geometer draws a line as part of a proof, that line is particular and has a determinate length. But it can still be taken as a way of representing any line in the context of that proof.
Likewise, I might be talking about dogs in general, but in my head, I probably have an image of specific Labradoodle. It's one specific dog, but I'm using the idea to think about dogs in general, in the abstract.
See? It's all down to earth and commonsensical, like most of my theories—once you understand them.