h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

'Picking holes huh?'

Of course.

'An omniscient god can presumably see the future. An omnipotent one can presumably alter that future. If the future changes it is no longer the future as previously seen making the omniscience flawed. If the future has to remain as seen then the omniscience falls down.'

An omniscient deity can presumably see all possible futures, and know which will come about, and what choices it will make, without the act of knowing forcing a particular choice. (There's a thread on time travel somewhere that covers a similar point.)

'What exactly is the universe if it's not 'everything there is'? 'God created the universe' immediately implies 'god created god'.'

Alternatively it may be that the word 'universe' is being used in two different senses. You didn't get the second quotation from my question; quite possibly you've got it from someone who was excluding God from his or her understanding of the word 'universe'. I asked about how a universe containing a deity would differ from one not containing a deity; had I been asking about universes created by deities and universes not created by deities I should of course have defined 'universe' differently.

'I have to question what sort of an onmipotent deity would not intervene'

A non-interventionist omnipotent deity. It's not a logical contradiction; indeed, by definition an omnipotent being does have non-intervention open to it as an option.

'if it did not, what is the difference between a god that is neither detectable nor has any influence and one which does not exist.'

One exists and the other doesn't.

Detectability depends on our capacities. As for influence, if only one object x existed in the universe (and that is not a logical contradiction), it would have no influence on any other object. Can it not exist? Suppose we introduce some other object y; does x now cease to exist unless it influences y? Is the existence of things dependent on their influencing each other, or is it necessary that they exist in order to influence each other?

'The flat Earth example was to put the reason for the belief in god/s into context with the current understanding of all the fundamental questions the 'god hypothesis' was designed to answer.'

However, that still isn't what I asked about. I want to know about scientific reasons for accepting or rejecting the hypothesis. You can ridicule the religious all you like without addressing my simple epistemological question.

'In particular a god that can do things the ordinary components of the universe cannot, a god which is therefore unknown and unknowable. Such a deity may be possible but it is a deity inconsistent with the universe in which it resides.'

'Ordinary' is a charged word, but anyway... You seem to have moved from undetected (except by the deity's own volition) and undetectable (except by the deity's own volition) to 'unknown and unknowable'. Note that when I set up the question I specifically asked about empirically observable features of the universe (which, given our definition of 'universe', would include empirically observable features, if any, of a deity). What we can potentially know and what we can practically detect are two different things; we can't even detect circles, but we can know circle theorems a priori. Even supposing it to be true that the deity is unknown, unknowable and able to do things that other (supposed) members of the set of things cannot, I fail to see why that would make the set of things an inconsistent set. Were you referring to logical inconsistency, or just saying that such a deity would differ fundamentally from the rest of the universe?

'Now you said:
"one doesn't need to know why something might exist in order to try to determine whether it does."

Which is probably true, because 'why' implies some kind of choice and is usually reserved for subjective things. 'Why' is a weak question normally excluded from the objective questions of science.

The statement 'one doesn't need to know HOW something might exist in order to try to determine whether it does.' however is very different.

In this case if we know enough about the 'how' we know whether existence is possible. For a giant tortoise to exist it had to have parents and it had to eat and breathe. A tortoise big enough to support the Earth would have to have come from somewhere big enough to produce and sustain it and this place would have to be supported on something. By inspection the tortoise hypothesis falls down and, in my opinion, so does the god hypothesis.'

'Why' meaning 'for what reason', or 'on account of what cause'.

You have mysteriously contrived to contradict your earlier assertion that the empirical evidence is not inconsistent with the existence of a deity. Which possibly explains your use of the word 'opinion', here unsupported.

'OK, there are usually other ways to determine whether something exists but in the absence of empirical evidence knowing how is often enough.'
But not in this case. All I asked about was the existence of a deity with the usual properties attributed by theologians. I didn't ask about how the deity might have come to exist, or how it might be sustained; I didn't ask about the existence of a giant human to correspond to the giant tortoise. How God exists, if He does, is merely unknown data.

Hi RFJS_,

The 'all possible futures' doesn't cut it. The universe absolutely must have one final, eventual future.

Given that the deity is undetectable then there is, logically (even tautologically), no empirical evidence to determine whether a universe contains a deity or not. I answered that quite clearly and we are seemingly in agreement about the conclusion.

All the other points arise because I went on to discuss whether there are other routes to making a deduction about whether a universe contains a deity.

Clearly the nature of the deity is an issue.

If the deity is undetectable; in fact, in practice, in principle or by definition then the conclusion holds but as soon as the deity either allows itself to be detected or simply is detected then there will be some empirical evidence. Whether that evidence is ever found is a different matter. In other words if God remains undetectable then science will never prove his existence. If he does not then science may or may not prove his existence dependant on whther they recognise the evidence. Detectability does not depend on our capabilities; the question asked only if there would be evidence, not if we would recognise it.

If the deity created the universe (while your example didn't state this many religions say their deity is the creator) there are questions of logic to be addressed so I brought these up. Your example suggested the Christian God as an example and he is understood to be the creator.

If the deity is non-interventionist then aside from spiritualist considerations the deity does not exist. It is undetectable and has no influence on any part of the universe. It falls into the definition of things which do not exist. If it is believed to exist however it also falls into the set of things which do not exist but are believed to do so - like Santa Claus, fairies and visiting aliens.

Similarly if there is one object in the universe then it does not exist; this zen-like situation is covered by quantum mechanics. Also two objects only exist when they influence each other and having done so cease to exist until they can influence each other again. A sub-atomic partical exists in all possible states (including no state at all; viz zero point energy) until either its position or velocity is measured.

I did not wish to ridicule any religious person. If you feel insulted then I'm sorry. Applying reasoning to religion is clearly an emotive issue; simply because much of religion does not stand to reason. If you disagree with the line of reasoning you are at liberty to say so, as you are doing here.

The why/how bit was something of a red herring but I had to say that 'why' is not a scientific question because of its implications of conscious intent. Your definition: "'Why' meaning 'for what reason', or 'on account of what cause'." imlies the same - 'reason' being clearly tied in with intent. The problem with 'why' being that, in the manner of a five year old child, you can keep asking it until you get to the reason for the beginning of the universe. There is no answer to 'why is the universe here?'

OK, 'ordinary' was a bit of a qualifier for a universe we can't see much of and certainly don't understand, I accept your argument.

You asked about "the existence of a deity with the usual properties attributed by theologians". I looked at some of those properties: undetectability, omnipotence, omniscience and creation in the light of your question. Undetectability defines the question as discussed above, omnipotence and omniscience are mutually exclusive and you say creation is excluded because it wasn't in your original question.

This leaves a self referencing conclusion: if there is an undetectable deity in the universe can we detect it? Answer: obviously not.

If the deity is not undetectable then there is a difference between a universe containing this deity and one not containing it. Whether we can detect it in practice was not part of the question; we can at least do so in principle.

F

Yes, we are in agreement about the original question.

I brought up 'all possible futures' simply because an omniscient being would have to know everything that could happen, as well as which of those things will happen. This was simply part of my point about omniscience not precluding omnipotence: 'An omniscient deity can presumably see all possible futures, and know which will come about, and what choices it will make, without the act of knowing forcing a particular choice.' If you prefer this can be simplified to: 'An omniscient deity can know the future without the act of knowing being the cause of its bringing about that future.' If determinism is true then the set of all possible futures and the set of all actual futures both have the same, indvidual member: the 'one final, eventual future'. If not, any omniscient being would have knowledge of the one final, eventual future, plus knowledge of what that future wasn't but could have been had the events determining what the future ended up as been different. In neither case is knowledge of a future, possible or definite, the cause of that future's coming about.

I didn't say creation was excluded from the debate; I said, in reference to your use of the word 'universe' in your argument, that the argument works only if the word is used both times in accordance with the definition I gave, and that had I been asking about creation my chosen definition would have been different.

'Detectability does not depend on our capabilities; the question asked only if there would be evidence, not if we would recognise it.'

It did; but the point of detectability was raised, and detectability does depend on the capablilites of the detector insofar as, if a deity were detectable by only method x, and a detector was incapable of using method x, then the deity would be undetectable insofar as that detector was concerned, but detectable insofar as a detector capable of using method x was concerned.

Your use of quantum physics is interesting, but it makes the assumption that the deity would be subject to quantum mechanics, which is an unwaranted assumption; I can postulate (without having to state its properties) any substance (for want of a better word; I'm using the word in an extremely broad sense for the sake of the argument) that isn't logically impossible as the stuff of which a deity might be composed (so to speak). Theogen may not fit your conceptions of the universe very well, but that fact alone doesn't constitute sufficient grounds for rejecting it; it would have to be actually impossible or demonstrably nonexistent. Indeed, the conventional Christian conception of God makes Him material only in the case of the Incarnation (with the Holy Spirit being quite clearly immaterial). In any case, an omniptotent being presumably has power over quantum physics.

'If the deity is non-interventionist then aside from spiritualist considerations the deity does not exist. It is undetectable and has no influence on any part of the universe.'

Detectability as I have discussed it is not a prerequisite for existence. Neither is influence if the argument from quantum theory is rejected. Besides, I can postulate the following: a deity, and some object x. The deity can influence x without influencing anything else in the universe. x is detectable, but only by the deity (unless the deity, in its omnipotence, wills otherwise). The rest of the universe goes on oblivious. It won't work for self-sustaining deities, but then, those deities needn't be composed of matter anyway.

Alternatively, I can bring in the role of God as the immanent sustainer of His creation and suggest that a deity can influence other things in the universe without it being apparent that this is occurring. Or the suggestion that God will be detectable in an afterlife. I don't have to limit myself to a supposedly omnipotent being (and in many conceptions the creator of everything other than Himself) who is nonetheless subservient to quantum mechanics.

No, I don't feel insulted; as far as I recall I never said on h2g2 whether I'm a theist or not anyway, so it doesn't follow from my comments that I'm one of the religious. My position in this debate is agnostic.

'"reason" being clearly tied in with intent'

Depending on how you interpret the word.

Otherwise we seem to be in agreement.

"Otherwise we seem to be in agreement."

OK, maybe we can meet over these points too.

The point of there being one final future, as logically there must be, is not that this is then the cause of that future coming about but that the deity can't change it. Because we ourselves can't see the future this is not an easy concept to grasp but let's try a simple example. Imagine you have a double-headed coin. Every time you toss the coin you know the outcome. With sufficiently dim-witted opponents you will win every time: if you can call 'heads'. In effect you know the future of every coin toss. Let's say you decide to buy a double-tailed coin too. Now you have the power to change the outcome but with it still under your control. With a little sleight of hand you can now even allow your opponent to call heads or tails and still guarantee to win. You can still win but you can no longer predict the outcome of the coin toss. You have exchanged the ability to change the outcome (omnipotence) for the ability to see the outcome in advance (omniscience) because you are not the only player in the game.

Detectable is detectable. The question was whether a universe containing a deity would be empirically different from one not containing a deity. Not whether any sentient inhabitants of either universe could detect the deity. The logic stands: if and only if the deity is detectable the universe is empirically different.

The issue of whether any entity which is undetectable (meaning really undetectable - not merely undetectable by any known or viable process) and non-influential actually exists is an interesting one. This is a bit deeper than the zen 'if a tree falls in a forest...' example but not entirely dissimilar to it. The quantum issue is valid for objects in the accepted sense - which you brought up - but clearly may not apply to a deity. I responded to your example but may have sneakily expanded the definition to apply to a deity too, although I don't remember doing so deliberately.

Some things always strike me as odd in arguments of this kind. Some of these are sweeping generalisations but they represent a kind of god's-logic employed by a large percentage of the people I've debated these issues with.
People (except probably Justin) assume that the deity is subject to the rules of logic and maths but not of physics. They seem to assume that, say, prayers will (sometimes) be answered, the sick will (occasionally) be healed and even miracles will (albeit rarely) happen. On the other hand they do not believe that god is constantly, say, feeding fuel to the sun or tweaking the orbits of the planets. I find this quite strange; that most people assume god is non-interventionist until something serious crops up in their lives. I'm not making a judgement here, just an observation.

There was a famous argument in the 19th century involving Darwin, some geologists (a new science then) and the great Lord Kelvin over the age of the Earth. Darwin argued that the process of evolution must have taken a very long time and the geologists and fossil collectors were beginning to point out that the rocks indicated the Earth was millions and possibly billions of years old. Kelvin insisted that it could not possibly be so old as it still has a molten core and would have cooled to a solid in that time. Kelvin and many of the scientists were practising Christians, some of whom were uneasy with the concept of evolution because of its contradiction of biblical creation. They were examining physical evidence to settle a borderline religious dispute but none of them suggested god's intervention with, say the heat within the Earth. In other words no-one ever seems to claim that god is 'working' the universe - merely that he set it running. I find this strange; if god is everywhere why don't more people think he's controlling everything too?

So, if we are to debate these issues we need to agree on some basic principles:
Is god subject to logic and/or mathematics?
Does this extend to the logically (not, note, empirically) derived rules of quantum mechanics and relativity?

F

'The point of there being one final future, as logically there must be, is not that this is then the cause of that future coming about but that the deity can't change it.'

I'm not entirely sure what the general principle is meant to be of which the simple example is an instance, but I'll analyse it as best I can. With the double headed coin alone there are two possible outcomes (since even a double-headed coin can land on either of two sides), each of which is 'heads'. Therefore you know that each of the two possible outcomes is 'heads'. Therefore you know that the outcome will be 'heads'.

With the two coins, you have a choice between the future described above and another which is identical except that each of the possible outcomes is 'tails'. Before you select your coin, the possible outcomes of the coin toss are 'heads' (twice) and 'tails' (twice): {h,h,t,t}. By your choice you limit the range of possible futures to {h,h} or {t,t}, i.e. to either 'heads' or 'tails'. So you determine whether the outcome will be 'heads' or 'tails'.

'With a little sleight of hand you can now even allow your opponent to call heads or tails and still guarantee to win. You can still win but you can no longer predict the outcome of the coin toss. You have exchanged the ability to change the outcome (omnipotence) for the ability to see the outcome in advance (omniscience) because you are not the only player in the game.'

At t1, which can be any time at which you have decided your strategy, you know in advance that you will select the coin not corresponding to what is called (assuming that at t1 you have already chosen to do so and will not change your mind). So at t1 there are (given the restriction of your choice) two possible futures: one in which 'heads' is called and the double-tailed coin is tossed, and one in which 'tails' is called and the double-headed coin is tossed; and no, you don't know which of them will come about. However, your knowledge is actually of the same type (if I may be permitted a loose application of the word 'type') as it was with one coin. You then knew that one of two possible futures would be the case -- both of them 'heads' futures, but not the same head. You now know that one of two possible futures will be the case -- both of them 'coin' futures, but not the same coin. Since you've already chosen to toss whichever coin causes you to win, your choices no longer affect the outcome unless you choose to stop tossing whichever coin causes you to win (and correspondingly, with one coin, your choices don't affect the outcome unless you choose to stop tossing a double-headed coin). Within the restrictions of your choices, you cannot affect the outcome. With one coin, you have restricted the range of possible outcomes to {h,h}, and which head comes up is random; fortunately for you it doesn't matter. With two coins, you have retricted the range of possible outcomes to {,}, and which comes up depends on what is called by someone else. (Sorry if I haven't used the proper set notation here; I'm not a statistician, so I borrowed the notation from first-order logic.)

So the two scenarios are actually equivalent: you choose a strategy that narrows down the range of possible outcomes, not to one possible outcome, but to a set of possible outcomes of which each results in victory. Your knowledge of the future is based on the range of possible futures you have selected; you know that in each possible future you will win, and therefore you know that in _the_ future you will win. Your degree of knowledge of whether the result of the coin toss will be heads or tails depends on the extent to which your choices have determined it. You have not 'exchanged the ability to change the outcome (omnipotence) for the ability to see the outcome in advance (omniscience)'.

What you don't know in advance, not being omniscient, is what you will choose; you don't know that you will decide to play the game in this way until you actually do it, and you don't know that you will decide to stop doing so until you do. If you were omniscient, you would have all the knowledge you would in the above example. You would also know which side of each coin would come up, and which of the two coins would be tossed (not that this knowledge would have any effect on whether you won or not); and you would know at t0 that at t1 you would choose to play the game in that way. Now that is a potential problem, given that the choice at t1 must determine both events at t2 and knowledge of those events at t2 which is held at t0.

One popular option is to remove the deity from the temporal realm, as it were, altogether. After all, an omnipotent being presumably has power over time. Alternatively, if all choices made by the omniscient being are made at t0 (and since the being knows everything at that time it might as well make the choices then as later), then the choices will be made merely at the same time as the knowledge is held, i.e. the being simultaneously chooses and knows what it has chosen. The first option is more consistent with omnipotence, however.

'if and only if the deity is detectable the universe is empirically different.'

Correct, given the possibility of indirect detection, i.e. by means of empirical evidence demonstrating that a deity definitely exists. I assumed that by introducing the term you were trying to communicate something distinct from 'empirically observable', but presumably you were just using 'detectable' as an alternative term. The point was that a deity need not depend for its existence on the possibility of detection by other entities.

'I find this quite strange; that most people assume god is non-interventionist until something serious crops up in their lives. I'm not making a judgement here, just an observation.'

Possibly the non-living part of the universe is felt not to need tweaking because its workings are already set up, whereas a personal deity might intervene where sentient beings with free will are concerned. God is sometimes held to be the sustainer of the universe, but not necessarily in such an obvious way as feeding fuel to the sun, more (I think) by willing the continued existence of His creation.

'if god is everywhere why don't more people think he's controlling everything too?'

For God to control _everything_ would be contrary to human free will, which in most religious traditions of which I'm aware we are held to have. As for the rest of everything, while God is widely seen as the sustainer of things (see above), I think believers tend to be quite content to think that he said, "Let there be light," and such was His power that the light could then take care of itself without God's having to intervene and will the creation of a photon every time a photon was required.

'Is god subject to logic and/or mathematics?
Does this extend to the logically (not, note, empirically) derived rules of quantum mechanics and relativity?'

The rules of physics, as far as I am aware, describe relations between numbers such that, if certain empirically derived numbers are plugged into them, others will follow as a result that describe the empirical universe, _if_ the mathematical model takes enough of the necessary figures into account. In the first place, while I'm not au fait with the equations of quantum mechanics and relativity theory, I suspect that trying to plug 'God' into them just isn't going to work; a numerical description of God would be required, and one, moreover, that consisted of values that could be plugged into the equations in question, which would be awkward if God willed that they couldn't. In the second place, the rules take no account of deities; therefore they need not be considered fully to describe universes containing deities. The full description of such a universe would presumably be {quantum mechanics}+{relativity}+{whatever else physicists may work out to get the first two to work together}+{God}.

As for logic and mathematics in abstracto -- simply put, it depends on how you define omnipotence. One can postulate a deity that has power over them, and one can postulate a deity that hasn't, and neither looks amenable to detection.

'Alternatively, if all choices made by the omniscient being are made at t0 (and since the being knows everything at that time it might as well make the choices then as later), then the choices will be made merely at the same time as the knowledge is held, i.e. the being simultaneously chooses and knows what it has chosen.'

Come to think of it, this one doesn't work for deities that have existed eternally, either.

Of course, I'm using an 'everyday' concept of time here.

OK so the double-headed coin was not a great example but you clearly get the general principle: knowledge of the same 'type' is not the same as actual knowledge.

I wasn't suggesting that god should be included in the equations of quantum mechanics or relativity - I was asking if god had to obey the laws these equations deduced; such as Heisenberg's uncertainty principle or the limitation of the speed of light.

F

As an omnipotent being, presumably not.