We used to think this world was all there was. We were wrong. We used to think this solar system was all there was. We were wrong. Some of us think that this universe is all there is. Especially in light of emerging evidence, isn't there a good chance that they, too, are wrong?

1) To what "evidence" are you referring?

2) Whether there may or may not be anything beyond, or outside, the physical universe is irrelevant to what happens to us when we die. To say that the universe is all there is has no implications for human death. And suppose perhaps that there is a universe beyond this one; it does not follow that we go there when we die.

I would say that the steady march of science is as much, if not more so, about what we know isn't true about the universe - a contraction of what we believe can be possible - as it is a process of expanding our horizons. Michaelson and Morley proving that there's no such thing as the luminiferous ether. Einstein proving that the speed of light cannot be exceeded. Bell proving that there's no hidden determinism. Call it Horatio's Retort - "there are more things dream't of in your philosophy, Hamlet, than are in Heaven and Earth."

But most of all, the idea of essences gave birth to the notion of the soul. It causes people to think erroneously that the information-processing activity of the mind is not just the product of the brain's functioning, but a separate thing in its own right that can exist independently and survive the death of the body. Given what we now know about how the brain works, this makes about as much sense as believing that a computer could continue to process data and display programs after its hard drive and CPU have been melted down.

I think a more apt metaphor would simply be disconnecting the computer from its power source, i.e. turning it off. That would be the equivalent of death to a computer, though it does lend the possibility of resurrection. ;)

In essence, Plato's fallacy was to divide the world into categories, and then assume that the categories themselves were real things that existed in their own right.

Plato's Forms are incredible. Plato believed that there was an unmoved-mover creator of the world, the immaterial Forms, and the material world in which all things were imperfect embodiements of their respective Forms. Plato also believed that all material things had a telos, or goal, such as for an acorn to become an oak tree and for an oak tree to become a chair.

There are several aspects that I love about this. Plato clearly distinguished between all of his concepts. The existance of Forms helped explain somewhat silly questions such as, "How do two different oak trees know what they are supposed to look like as they grow?" Telos explained things such as, "Why does an acorn turn into an oak tree and not into a chicken?" He concluded from this that the goal of humans should be to become as close as possible to the Form of a human. Meanwhile, the creator had nothing to do with any of this.

What I like about Plato is that his entire theory is actually intended to answer some very basic questions. He doesn't try to wrap his ideas in mysterious concepts like subsequent religions did. Consider how analogous it is to the Holy Trinity. You have God the unmoved mover, Jesus the perfect Form, and the Holy Spirit, which is how we are related to our Form. We have roughly the same concepts on the one hand to explain the natural order, on the other hand to deify and worship an all-powerful god. I guess my question is how did we go from Plato to Christianity - what happened?

I envision it as a tiny monkey (maybe like one of those golden lion tamarind that look like little bearded old men) inside my hard drive furiously switching wires like a 1940's-era phone operator. Sometimes he gets tangled up. Other times, you tell him to unplug something but he can't get the plug out and he's in there with his little feet planted against the wall of the drive, yanking for all he's worth.

THAT is what I'm convinced is going on when you tell the Windows Task Manager to shut down a frozen program . . . and nothing happens.

Plato's fallacy was to divide the world into categories, and then assume that the categories themselves were real things that existed in their own right.

That's the bit I was missing.Thanks

In short, we're susceptible to reification.

Heh... Rhetorical question: Do numbers "exist"? What kind of "thing" is a number?

I like that concept, actually. There is a strong element of continuity in SOCIETY -- not an individual soul, but perhaps an aggregate one of sorts. For example, there is an unbroken chain of American Presidents from Washington to Obama. Even though Obama was elected over a hundred years after, say, Lincoln, the votes were tallied in the same way in 1860 as in 2008, through the electoral college. Things have changed -- new categories of people are permitted to vote, for instance -- but the basic process is still there.

I feel the same way about individual "souls." I don't expect to live on in any way that would allow me to sense things (and I find particularly telling the point that a soul would not, technically, have any senses to do soul-things WITH). But my genes will live on, and so will my ideas and beliefs. Whether I simply share them with others, or teach them to friends and family. My mother lives on not just in my genes but in my memories -- the latter is not a tangible sense at all, but it remains meaningful to me nonetheless.

And what more do I need?

I've never been able to understand how this idea can peacefully coexist with reincarnation.

My understanding of the matter is that Buddhism believes the human mind to be made up of changeable aggregates, called skandhas, which create the illusion of a self when they combine in certain ways. When you die, those aggregates can dissolve and recombine into new forms, which are not "you" but which bear the causal imprint of actions they took part in in the past.

The usual analogy is using one candle to light another, and that one to light still another, and so on. You wouldn't say that later candle flames are reincarnations of the earlier ones in any meaningful sense, but there is still a consistent chain of causality that flows through the entire series.

I've never been able to understand how this idea can peacefully coexist with reincarnation.

Neither have I, and this is probably the only reason that I'm not a Buddhist.

could you clarify for me why "eternal forms" should also be a result of this kind of mind?

Christopher gives a nice, succinct explanation of Plato's general idea, and here is a simple, specific example. Think about chairs, all the chairs you have ever encountered, and what exactly it is that makes a chair be a chair (aside from "that's what people call it"). According to Plato, all physical chairs are imperfect Earthly incarnations of some metaphysical "chairness," a Platonic form of Chair which inheres in chair-like objects and makes them be chairs. It is this "essence of chair" that makes Earthly chairs "chair-like." This is, of course, metaphysically backwards: it is not any ethereal "chairness" that makes chairs chair-like, but rather that human chair-makers have some idea of a chair in mind when they craft such things, and it is only our familiarity with these patterns which causes us to recognize chairs as chairs - not some mystical chairness. In other words, Plato supposed that chairness is in Earthly chairs, and this essence is what fuels our thoughts of chairs; in reality, Earthly chairs are simply "atoms arranged chair-wise," and "chair-wise" is nothing but a pattern in our heads which we impose upon the world (mentally, when recognizing chairs; physically, when making chairs).

After writing "chair" so many times, that word just looks wrong to me. At any rate, the point is that this kind of mindset (that there is a "higher realm" of which this Earthly plane is merely an imperfect reflection, or trial run, or what-have-you) fuels a whole lot of superstitious nonsense. Not just Plato's forms, but also humanity being made in some deity's image, or archetypal deities, or whatever your dualistic superstition du jour may be. The dualism is all in our heads - there is no higher realm, there is only the reality in which we find ourselves, however convoluted or counterintuitive it may be (our intuitions, after all, are merely artifacts of evolutionary convenience). Now apply this idea to things like "beer galaxies," and we see that any supposed "weirdness" we find is also all in our heads: the Universe simply is the way it is, and it is only our preconceived notions of "how things should be" which are shattered upon encountering the mind-blowing reality of... well, reality. There simply is no "way things should be," metaphysically; there is only the way things are, and the ever-narrowing-yet-never-closing gulf between that and our conceptions of it.

TL;DR version: Dualism, in all its flavors, is nothing but an attempt to bridge the gap between reality and our conception of it, without actually going to the trouble of empirically traversing it as far as we are able.

[Is it not reasonable to suppose] that perhaps, as our Earthist views of life eventually crumbled, that perhaps one day our Universist views of life will also crumble, too?

Perhaps, cl; but that depends on how we define "Universe." For my own part, I define "the Universe" as "all that exists," whether or not certain of those existents may interact in any way at all with certain others. In other words, if there are "multiple Universes" (in the common parlance), I see them all simply as "facets" of one single multifaceted Universe. As for whether or not a "multifaceted Universe" is the case, I simply withhold belief one way or another (but I am epistemologically prepared for evidence either way).

To get at the meat of your question (or at least, as I understand it), a highly qualified "yes" is my answer. Yes, it is possible (as far as I know) for all manner of crazy things to actually be the case, whether or not we have any power to discover, verify, or even conceive of such things - and it is reasonable to recognize that our expectations in any field may yet be wildly defied by reality. However - this is the qualifier I was talking about - whether something actually is the case and whether it is reasonable to believe in that something are two entirely separate matters that depend on a wide variety of factors.

For instance, suppose that Socrates had had a completely accurate vision of the large hadron collider being used to create and observe low-mass singularities (or, in the error-fraught but exciting lingo of today, "tiny black holes"). Would he have been correct to put a huge amount of epistemological stock in this vision coming true? We know today that he would have been. But would it have been reasonable, rational, or justified for him to do so? Absolutely not. Similarly, were I to suddenly have a vision of the Judaeo-Christian deity spouting some noise at me, I am bound by rationality to discard that as a neurological misfiring - it is simply more likely that I went a little crazy for a moment than that such an entity actually exists as laid out in those books. Were I to place any significant amount of belief in the contents of that vision, true or not, I would be behaving irrationally.

I think we all have times when we're feeling metaphysically slutty, so to speak, but we need to remember at the end of the day that, for us to remain rational, we must tie down our actual beliefs to evidence and sound argument. Playing fast & loose with our metaphysics makes for exciting sci-fi and fantasy, and fuels the imagination in ways that can benefit real science - but it is no guide whatsoever to verifiable or actionable facts, and we must be careful not to mix up the two.

At the end of the day, I think the point is that although we can never be absolutely certain whether proposition X is or is not the case (because we cannot have second-order knowledge), it is simply entirely unreasonable for educated persons living at a time such as this to believe in the supernatural, given the overwhelming body of evidence (both formal and informal) that is available to us. At the public level, we must maintain freedom of conscience as a matter of ethics, which means that we are within our rights to believe whatever we want - but to attempt to regulate the lives of others based on epistemologically empty propositions is morally reprehensible, which is why secularism is the way to go.