Can the existence of God be demonstrated by logic?

[McCulloch]

I believe that the following facets of my faith can be demonstrated by logical deduction
1. There is a God

Can the existence of God be demonstrated by logical deduction?

[EduChris]

...It is unreasonable to believe that something is objectively true without being able to argue that it is objectively true. Wouldn't it be more intellectually honest to say that you believe that is it probably true if that is all you can support with evidence?...

I believe that it is objectively true that other minds exists. But I cannot prove this by any objective means. Do you think it is unreasonable for me to believe that other minds exist? Similarly, I believe that logic is a useful tool for determining truth--but I can't prove it objectively. I also believe that cause and effect is a valid description of how the physical world operates--but I can't prove this by any objective means. It seems to me that all of us very often believe things we can't prove by any objective means.

...This so called problem is not really a problem at all. Emergent characteristics are well known. For example, individual buyers and sellers are unpredictable and somewhat fickle. However, large numbers of buyers and sellers in a free marketplace behave as if certain economic laws were in place. The entire field of study called macro-economics is based on a principle which according to EduChris vacate the very notion of logic and reason.

Subjective mental experience cannot be equated to individual or collective purchasing patterns. Presumably, given materialism and advanced technology, individual purchasing patterns might one day be foretold with the same accuracy as collective patterns. Individually or collectively, there is still buying and selling going on. Subjective mental experience, on the other hand, is an entirely new phenomenon. Previously you suggested that wetness is an emergent property of water, since neither hydrogen nor oxygen have the property of wetness. But here again you are wrong--hydrogen and oxygen can be found in liquid form. And a single molecule of water could hardly be called "wet." It might be useful if you could come up with some better analogy.

[McCulloch]

It is unreasonable to believe that something is objectively true without being able to argue that it is objectively true. Wouldn't it be more intellectually honest to say that you believe that is it probably true if that is all you can support with evidence?

I believe that it is objectively true that other minds exists. But I cannot prove this by any objective means. Do you think it is unreasonable for me to believe that other minds exist? Similarly, I believe that logic is a useful tool for determining truth--but I can't prove it objectively. I also believe that cause and effect is a valid description of how the physical world operates--but I can't prove this by any objective means. It seems to me that all of us very often believe things we can't prove by any objective means.

Don't we call those things we must assume to be true, without objective proof, axioms? Are you arguing that God is axiomatically true, thus ending the debate before it even starts?

Subjective mental experience cannot be equated to individual or collective purchasing patterns.

No, but they are analogous. The fact is that macro-economic theory only works when there are significantly large populations engaged in a marketplace. It does not apply for small numbers, yet remains true. Mental attributes are not detectable at the cellular level, yet emerge in complex multicellular organisms.

Presumably, given materialism and advanced technology, individual purchasing patterns might one day be foretold with the same accuracy as collective patterns.

I doubt it.

Individually or collectively, there is still buying and selling going on. Subjective mental experience, on the other hand, is an entirely new phenomenon. Previously you suggested that wetness is an emergent property of water, since neither hydrogen nor oxygen have the property of wetness. But here again you are wrong--hydrogen and oxygen can be found in liquid form. And a single molecule of water could hardly be called "wet." It might be useful if you could come up with some better analogy.

A single neuron can hardly be called intelligent. Yet a fully functioning brain is. The analogy still works for me.

[McCulloch]

Just as the existence of a 44th president demands a first,
the existence of causes and effects demands a first cause.
The Cause must necessarily be uncaused and either eternal or outside our frame of reference in space-time to say the least. The only alternative is an infinite number of causes.

William Lane Craig put it this way:
Whatever begins to exist has a cause.
The universe began to exist.
Therefore, the universe has a cause.

Unless there is evidence that one thing which began to exist did not have a cause, or that the universe did not begin to exist, then the conclusion was reached by an argument that is both valid and sound.
It's not about assuming theism, it's that all the evidence points to theism, and no evidence exists that would support atheism.

Did the universe begin to exist? To begin to exist implies that there was a time when the universe did not exist. There is no evidence whatsoever that there was a time when the universe did not exist. Time is an integral part of the universe. There was no before time started, thus there was no before the universe existed.

[jimvansage]

An eternal universe?
What about the Big Bang, the 2nd Law of Thermodynamics, and everything else we understand about the universe.
I thought the scientific consensus was (because of dopplar shift in Hubble and other telescopes) that the universe is expanding and the expansion is accelerating?
Does that mean that the universe and time will never end?
Please explain how one can know that the universe is eternal.

[Mithrae]

Subjective mental experience cannot be equated to individual or collective purchasing patterns.

No, but they are analogous. The fact is that macro-economic theory only works when there are significantly large populations engaged in a marketplace. It does not apply for small numbers, yet remains true. Mental attributes are not detectable at the cellular level, yet emerge in complex multicellular organisms.

An individual's choice to engage in any given economic activity will have a probability between 0 and 1; studying the behaviour of large numbers of people simply improves the accuracy with which we can predict it. The behaviours are present in each unit - unlike what's proposed in the case of mental attributes.

EduChris and yourself may be interested in parts of a discussion between TGA and myself on this very subject, in my thread Knowledge from first principles (C&A forum):

• Mithrae wrote in post 24:
  'Sum of the parts' might not be the best phrase to be using; I don't mean to imply simplicity in any of this, and (regarding your chemistry example) nor do I mean to imply that all the properties or interactions of the parts individually should be present in the whole. On the other hand 'sum of the parts' is a good phrase when discussing something like the earth's mass and gravitational effect
  
  But what I mean is simply that as far as I'm aware, above the molecular level we do not ever see something objectively new. This may or may not be the case at the atomic and quantum level also, but I've seen some scary talk of 'virtual particles,' and particle/antiparticle pairs popping into existence and annihilating, and wave/particle thingies which can be in two places at once (apparently observed even in molecules up to 114 atoms). So I'd rather steer clear of those murky depths, unless and until anyone suggests that subjective experience arises at the quantum level - that could make for some very interesting speculation!
  
  The parts, their properties and their interactions needn't be obvious or easily worked out, but as far as I'm aware - in the case of everything from supernovae to black holes, hurricanes to pizza, table salt to even the properties and processes of 'life' itself - above the molecular level we do not ever say that something objectively new has arisen. That would pretty much be magic, after all. The capacity to produce subjective experience is the one and only exception to this that I'm aware of, if and only if we suppose that subjective experience is foreign to the nature and properties of molecules.

• Mithrae wrote in post 36:

  A> Can we coherently and justifiably describe subjective experience in such a way that the capacity to generate it is not an objectively new property given 'physical' reality?
  
  B> Can we show that subjective experience is unique to neural networks and not present (as possibly the best example) in bacteria?

  A> The capacity to generate subjective experience is inherent in the physics of the world just like the capacity to generate stars. Stars did not come about until the universe has evolved to the point where stars were possible. Stars were a new expression of increased complexity of existing conditions . The neurological processes that support what we call subjective experience did not come about until neurology had evolved to the point where subjective experience was possible. Subjective experience is a new expression of increased complexity of existing conditions. Show me the capacity to generate subjective experience independent of a physical substrate. Otherwise it is not an objectively new property.

  In short if it happened in the physical universe, then it is inherent in the physics of the universe: Since the appearance of an objectively new property in the sense we've discussed would be absurd, it follows that generation of subjective experience is not an objectively new property.
  
  Obviously that's a tautology that I agree with, but I don't think that you've addressed the fundamental differentness of subjective experience. As I understand it (been reading A Brief History of Time recently) the characteristics of stars - gravity, pressure, fusion, heat, light - were all around before stars came to be; they're a combination of those things in a certain manner, if not precisely the sum of their parts then at least something along those lines. But it seems to me there's at least three characteristics of subjective experience which are wholly unique:
  
  Observation, obviously. You yourself highlighted the distinction between objective reality and subjective observer in your post above and earlier in post 25:
  It is a well demonstrated fact that quantum interactions that do not have a necessary permanent effect on the world at large remain in an unresolved state. One way of making such interactions have such a permanent effect is to observe them. The fact that unresolved states do exist tells us that there is no universal observer, at least not of anything distinct from that observer.
  
  Unobservable. Whereas two people looking at the same star or rainbow will generally see and experience the same things, that's not the case with subjective experience. Even in a hypothetical future in which technology could fully map out and display a person's memories or emotions, they still couldn't be experienced in the same way by another person without essentially erasing their own 'self' - replacing their memories and playing around with their endocrine system and brain chemistry.
  
  Unreal things. Where perceptions differ (and arguably where it begins) we find the sole example in the universe of things that aren't real. Colours or sounds aren't real things for example, but to avoid raising too much question over what is 'real' we can just as easily look at dreams, imagination and fantasy. As the objects of thought, its functioning and its products these three make sense of course: The question for anyone supposing that reality is non-thinking is how their generation could possibly be considered anything other than an objectively new property.

As far as I'm aware, above the molecular level (at least) consciousness or subjective experience is the only example of 'emergence' which isn't either a subjective perspective on phenomena (eg. 'wetness,' rainbows or the like) or the interaction of a thing's parts viewed on a larger scale (eg. macro-economics, stars, states of matter). I've never seen anything even remotely analogous to the development of characteristics as unique or different as those of subjective experience from parts which supposedly do not have them.

[McCulloch]

An eternal universe?
What about the Big Bang, the 2nd Law of Thermodynamics, and everything else we understand about the universe.
I thought the scientific consensus was (because of dopplar shift in Hubble and other telescopes) that the universe is expanding and the expansion is accelerating?
Does that mean that the universe and time will never end?
Please explain how one can know that the universe is eternal.

There is a distinction between eternal and infinite. Infinite would mean that the universe would be like the integers, no end, no limit, always one more, both in the negative (past) and positive (future) directions. Eternal would mean for all time. For those who believe that time is infinite, these two terms mean the same thing. However, relativity shows that time and space are intertwined and that probably neither time nor space is infinite.

So when I say that the universe is eternal, I mean that the universe has existed for all time. There was no time before the universe existed, since the space time continuum itself is part of the universe not an external framework that the universe exists within. So my view of an eternal but finite universe fits well with what we know about cosmology. I hope that helps.

[EduChris]

...Are you arguing that God is axiomatically true, thus ending the debate before it even starts? ...

Igtheism tries to end the debate before it starts; it does this by refusing to accept clear definitions of God as "the not-less-than-personal fount of all possibility and all reality and all existence and all being." Yes, this is a mouthful, but it's hardly unintelligible per the norms of the English language.

But yes, since there is no empirical evidence for or against theism (theism and non-theism are opposing metaphysical viewpoints) it follows that theism and non-theism are each axioms, starting points for any argument. And if we start with each axiom in turn, and examine the logical consequences of each, it follows that theism turns out to be the logically preferred philosophical position.

...A single neuron can hardly be called intelligent. Yet a fully functioning brain is. The analogy still works for me.

"Wetness" of water is a subjective mental experience, like the color "red." Conscious intelligence is something entirely new, and moreover it is the very thing by which we evaluate and experience all reality. That your analogy "works" for you is nice and all, but it hardly overcomes the obstacle that the strikingly new feature of consciousness presents.

[olavisjo]

relativity shows that time and space are intertwined and that probably neither time nor space is infinite.

For what it is worth, space must be infinite or there would have to be an end of space somewhere out there, then what would be beyond that end? And even if it wraps in on itself and we would be trapped inside a large container of some strange geometry, there would still have to be some space that contains the container that we are trapped in.
The idea that space is finite, is illogical.

[ThatGirlAgain]

relativity shows that time and space are intertwined and that probably neither time nor space is infinite.

For what it is worth, space must be infinite or there would have to be an end of space somewhere out there, then what would be beyond that end? And even if it wraps in on itself and we would be trapped inside a large container of some strange geometry, there would still have to be some space that contains the container that we are trapped in.
The idea that space is finite, is illogical.

You are assuming that Euclidean geometry is the a priori norm. It is a much more convenient abstraction for use by humans than non-Euclidean forms, to be sure. But if General Relativity is right - and it certainly appears to be at least a very good approximation - then there is in reality no Euclidean geometry existing anywhere. Presuming that Euclidean geometry actually exists is not justified. There is no reason to postulate the existence of a Euclidean hyperspace in which our non-Euclidean universe is embedded.

[McCulloch]

relativity shows that time and space are intertwined and that probably neither time nor space is infinite.

For what it is worth, space must be infinite or there would have to be an end of space somewhere out there, then what would be beyond that end? And even if it wraps in on itself and we would be trapped inside a large container of some strange geometry, there would still have to be some space that contains the container that we are trapped in.
The idea that space is finite, is illogical.

The universe of many old arcade games is both finite and unbounded. You do not bang into the top when you go up, but you end up back at the bottom. There are cosmologists who propose that the universe is both finite and unbounded, in the shape of a dodecahedron. This is only one such model.

Space might be finite but, like the surface of the earth, there may be no boundary. In fact, space is expanding. Can something that is said to be infinite be expanding?

See also: The Wraparound Universe
Jean-Pierre Luminet (translated by Eric Novak)
2008 A K Peters