Wiccan_Child said:
Agreed. Which is why I added the qualifier 'in the absence of prohibition'.
However, there are occasions when these laws do not describe precisely what will happen, only what can't happen. In these cases, what can happen may actually happen.
If it is possible, though by no means guaranteed, for a particle to pop into existence, then a particle may indeed pop into existence, uncaused and without purpose. It exists because it can exist, not because it must exist.
I'll make these remarks:
1. What you are saying now is very different from your original statement that "quantum mechanically, in the absence of any prohibition, anything that can happened will, eventually, happen."
2. My original point was that there is a sufficient reason/explanation for why something is. Quantum Mechanics does not provide a counter example (nor were you trying to give one - you were just trying to be clearer about what I meant, I think)
3. I think it is far too premature in our scientific endeavours to claim that these virtual particles are "uncaused". And causation is certainly not the only thing we must consider. There is a reason why the square root of two is irrational, but we wouldn't say something causes it. Even if they turn out uncaused, this doesn't spell a counter example to my claim if there is a sufficient reason. There is, for example, a sufficient reason why the square root of two is irrational
4. I think we would want to say more than just "It exists because it can exist". Though this is certainly part of the story, it is true for everything that exists. At the very least, things exist because they can exist, but that's a trivial claim. If you want to say that the sufficient reason why they exist is simply because they can, that's not the full story, and it certainly invites further scientific (or mathematical) enquiry. Perhaps the true story ends up being "there are n possible outcomes, each with probability p(n). The universe is at heart probabilistic, so nothing beyond raw randomness informed by these probabilities decides, and so the one that occurs occurred by a chance equal to p(x) of that event", or something like that. But that's more than just saying "It exists because it can exist". And then we would have the further question, "why is the universe probabilistic?", "what determines these probabilities?", etc. Especially because it seems that a deterministic universe could exist. Since it's not logically necessary that our universe be probabilistic at heart, and so this invites further questions. And personally, I'm not persuaded by the Copenhagen interpretation of Quantum Physics, but even if it turns out to be right that doesn't present a problem for me.
That's quite a few thoughts actually

Make of them what you will.
I remind you that my original point was simply this: positing a history that is infinitely long into the past does not escape some equivalent of a first cause. Perhaps you'll respond, "yes, but a first cause doesn't get you God anyway". Fine - we can discuss that instead if you like. But that doesn't do anything to counter my claim that an infinitely long history in the past doesn't escape a first cause equivalence. The universe being finite into the past is essential for the kalam cosmological argument, but not the leibnizian one.
Wiccan_Child said:
I think of science as the acquisition of probable truth, asymptotically to the actual truth, whatever that truth might be. If magic is the true answer, then that is what science will, in principle, eventually conclude.
Again by magic I mean something insulting

When you talk about science discovering magic, you're thinking of magic as being something accessible, able to be studied. When I say magic, I just mean things happening without any good reason, out of the blue. Perhaps a blatant *permanent* violation of conservation laws (ie, not virtual particles where the energy borrowed is later paid paid). The derogatory sorts of magic that atheists often accuse theists of believing in. The sort that resists scientific exploration. This sort of magic is not accessible by scientific means.
Wiccan_Child said:
(Referring to Plantinga's argument)
I'm aware of the argument, but I consider it bunk. That our rationality is evolved doesn't negate its effectiveness.
I know you're just making a short response, but again this depends on your definition of effectiveness. The most obvious example of measuring effectiveness is survivability, if we're talking in an evolutionary context. Our rationality may or may not be effective given that question - but it's entirely irrelevant to what we are discussing. If you mean its effectiveness at arriving at true conclusions, or something like that - well - Plantinga's argument wasn't trying to show that our mind (given evolution) is not rational, or able to arrive at true conclusions. His point was that if evolution, naturalism, and atheism is true (or perhaps he had a different trio of assumptions), then we cannot
trust our mind to arrive at true conclusions. It may very well turn out to be right most of the time, it may turn out wrong. The point is, we have no way of knowing, and indeed, the probability of it being poor at this kind of task is high. Therefore, his argument runs, we have a defeater for every one of our beliefs, including naturalism, if we hold to those beliefs. Moreover, this defeater cannot be defeated. Thus, if someone holds to that trio of beliefs, they have an undefeated defeater for virtually all their beliefs, including their ones that gave them this defeater. There is no escape from scepticism other than to reject some premise, such as atheism or naturalism.
Do you have a defence against his argument?
Wiccan_Child said:
Philosophically, it's sound. I also think it successfully avoids the 'first cause' issue: it is a valid alternative to the idea that the universe began with a first cause.
It is neither philosophically sound, nor does it avoid something similar to the 'first cause' issue. Again - if you hold to something like the principle of sufficient reason, there must be a reason why this infinitely long history into the past exists, and exists in the way it does. What is the reason for
that? I'm not sure that you've addressed that objection, other than to spring "because of Quantum Mechanics!" as some sort of get-out-of-jail-free card, which atheist's seem to do quite frequently when the mood suits
Wiccan_Child said:
That's one of the major flaws of Aquinus' arguments: they arbitrarily leap from 'First Cause' to 'God' to 'God of Christianity'.
It's not at all arbitrary

But quite often, it's not fleshed out. That's not the same as to say there are no such arguments, or that they're bad. But it might be good if we focus on the main contention.
Wiccan_Child said:
Hmm, that wasn't exactly what I was asking. I was asking why God can exist forever but the universe can't. But let's go down this route anyway.
That's the key, isn't it? If God is atemporal, you don't say "God can exist forever", because that implies He is a temporal being that extends all of time. You say, "God is timeless", for example. The "eternity" you propose for the universe is
fundamentally different to that proposed for God. The universe you propose is temporal, and extends throughout all time. Whereas for God, it is claimed that He is timeless/atemporal, and that is the sense in which He is "eternal".
Wiccan_Child said:
I'm not sure what Hilbert's hotel has to do with anything
The universe being infinitely old into the past is a case of an actual infinity of things. Hilbert's hotel shows, at the very least, the absurdities involved in an actual infinity - and at the very best, the downright impossibility of an actual infinity of things. We have infinity in mathematics - but in reality? That's a whole different ball game. That's the relevance of Hilbert's hotel.
Wiccan_Child said:
I disagree. If the past is infinitely long, then we have an infinite amount of moments which, when summed with appropriate limits, reach any finite number we choose. This is the fundamental principle of calculus.
There is, again, a key difference here. Let us say your function is y = 2. Now let's simulate the past being infinitely old. Our sum goes from negative infinity (the past) until now (0, or any absolutely specified value). This integral will not produce a finite number at all.
Now why is this relevant? Because when we're talking about the real world, we're talking about steps that take a minimum finite amount. And if our function y has a minimum greater than 0, it will sum to infinity in the integral. Time is considered to have a smallest unit, so is energy. The universe appears quantised in many important areas.
Consider Zeno's paradox. To get from a to b you must cross half the distance between them, and then half the remaining distance, and half whats left again, so on until infinity. Therefore, you never reach the destination.
The problem with this paradox involves the infinite divisibility of the distances involved. When we sum the distance to travel, even though the distance is infinitely divisible, the distance itself sums to a finite number. But this is absolutely not true in the case of a universe infinitely old. The amount we measure is not "reducing" commensurately fast enough to keep the final value finite.
Now to my original point that an infinity cannot be obtained by adding one to the other. To say this is possible is to say that it's possible (for example) to enumerate all negative numbers,
ending at 0. Clearly absurd. The simple fact is, we cannot get an infinity by adding one thing to the next.
Wiccan_Child said:
This argument is tantamount to disproving all of continuous statistics! For shame!
Consider a continuous variable x that can take any value in a given range of finite length. We measure the variable, and it comes up as having the value X. But wait! The odds that x would turn out to be X is exactly zero!
But that's the problem with a continuous variable: there's an infinite number of possibilities, so the odds that any particular one would arise is zero. But one value must nonetheless arise.
I would say it's a highly questionable claim that time is continuous rather than discrete. Certainly in most cases we can treat it as continuous (classical mechanical situations, for example), but this doesn't hold for all scales.
At any rate, I don't quite understand your argument that my claim amounts to disproving all of continuous statistics. Perhaps I'm a bit tired - could you make the reductio ad absurdum more clear please?
Wiccan_Child said:
I disagree. At best, the evidence shows the universe appears to have expanded from a singularity for approximately 13.5 billion years - otherwise known as the Big Bang. There is nothing in cosmology that suggests this singularity was the beginning of the universe.
Not only does it imply a beginning of the universe, but a beginning of time itself. This is the current theory. There are many attempts to try to avoid this, but from my last look, none are considered successful.
Regarding the argument that demonstrates that cyclical universe models must lead to a "singularity" of universes, the paper I was thinking of is actually talking about inflationary models of the universe. The problem with cyclical universes is one of entropy. Anyway, to the articles for inflationary model(I must confess I have not read nor tried to understand their arguments):
Arvind Borde and Alexander Vilenkin, "Eternal inflation and the initial singularity", Phys. Rev. Lett. 72, 3305 (1994)
Arvind Borde, "Open and closed universes, initial singularities, and inflation", Phys. Rev. D 50, 3692 (1994)
And for cyclic universes:
I D Novikov and Y B Zel'dovich, "Physical Processes Near Cosmological Singularities" Annual Review of Astronomy and Astrophysics, Vol. 11: 387-412 (particularly pages 401-402
At the very least, it is not clear that the universe is infinite in the past, that that is even possible, or that it escapes the 'first cause' in 'first cause' style arguments for God's existence. And making assumptions about the universe which attempt to avoid a beginning will commit the atheist to cosmological models with a certainty well beyond what the evidence allows.