Prof Alvin Plantinga on Reasons for God

Alvin Plantinga, Professor of Philosophy at the University of Notre Dame, discusses the reasons for God with Simon Smart from the Centre for Public Christianity.


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12 Responses to Prof Alvin Plantinga on Reasons for God

  1. tildeb says:

    tildeb: Besides the usual case of begging the question, Plantinga makes a rather remarkable assertion: because we do not have any evidence against the possibility of there being an omniscient, omnipresent, omnipotent, benevolent god – an entity of maximal greatness and maximal excellence – it might be reasonable to suppose such an entity has an existence probability of .5, that the premise that such a critter exists is either true or it is not.

    The two claims of equal probability – true or not true – is only an acceptable starting position before the undertaking of any inquiry into the actual existence of such a critter, but without substantive evidence for a positive probability, the reasonable conclusion is not equal possibility; the reasonable conclusion is that the premises are false.

    Failure to understand and appreciate what mathematical probability represents in the real world – merely a snapshot at a specific time and place – is a typical problem in ontological reasoning. It is a problem because it neatly overlooks the obvious: if there is no evidence to support a positive premise that something exists – that something is true – then the probability of the negative premise that something does not exist – that something is not true – increases accordingly. With no evidence in support of the positive probability… snapshot after snapshot after snapshot… the probability of the negative premise rises with each attempt until it approaches 1. This renders the ontological argument baseless as a means of inquiry, of having a reason other than wordplay to establish what is probably true, probably correct, probably accurate.

    If you think of it in a different way, you may see the point more easily: let’s apply the argument in a different context.

    I am either watching you or I am not. The probability before any inquiry is undertaken is .5. It may be true or it may be false. Because you cannot establish any evidence against the possibility that I am watching you as soon as I am finished posting this response does not mean that the chances remain stable at .5 regardless of any further inquiry. As soon as you begin to investigate the possibility and discover that there is no evidence FOR the watching, the probability of me watching decreases. The more you investigate, the more evidence you will uncover that I am not watching, which then gives you every reason to conclude that I am not watching with a probability approaching 1. That is the reasonable conclusion in the absence of positive evidence.

    Defend the Word: Your whole point revolves around the argument of examination and your ability to understand this evidence. And you should never forget that, you could do that when you deal with material things that are readily available and testable, in the way that you want them to be tested. And this is precisely what Dr Plantinga says, when you have insufficient data, with limited methodology that could not possibly assert this information positively or otherwise you are limited with probability analysis.

    This is exactly what Dr David Berlinski says and this is why he calls himself agnostic though he strongly supports those who believe in God. And guess what he is the lecturer of Maths so your argument stands only with those who don’t have full data and will be happy to take your word for it. But in the real world we have to accept that our faith plays major part in how we both understand and interpret this data.

  2. tildeb says:

    Also, Plantinga’s assertion that beliefs undergo a reduction through natural selection requires evidence for his assertion to remain probably true. He has not included any potential evolutionary benefit of maintaining unjustified beliefs but has stuck with only the ontological understanding. But it’s a real world out there and it will still require a buck fifty along with right or wrong beliefs to purchase a coffee.

  3. tildeb says:

    Let’s assume your point is true, that the problem with evidence is that perhaps simply don’t understand where or even what it may be. The next question is thus of vital consideration: why should a god who wants his presence known, hide evidence for this presence from us? Why does god need to hide?

  4. No lets not assume anything, on the contrary I have given you plenty of evidence which you dismissed. Many biblical prophecies have been fulfilled and fact that Jesus came is a mega clue to us all. If you check Old testament prophesise literally hundreds and see them fulfilled in Him you then have to decide if that information is good enough for you. I think it is but you have to make up your own mind up.

  5. tildeb says:

    Tildeb: But the prophesies were filled after the fact regarding Jesus, but just as relevant to hundreds of so-called prophets before Jesus. The problem here is how to differentiate. And as I’ve outlined before, evidence for divinity is as poor as it can get: “I know a guy who knows a guy who says he knows someone who was there…” That’s terrible evidence considering what a god should be able to provide to establish proof. What this evidence does provide for us – especially concerning factual claims supposedly made by Jesus – is every reason to remain highly skeptical.

    Defend the Word: You should first study this subject before you make such sweeping statements. First of all prophesises that you are talking about are often not prophesies about person but about events. All other prophesise about specific person are very narrowly focused on the person of messiah, and if you can find the equivalent that predates the actual person by a minimum of 400 years and in the volume that they are foretelling his coming then I would like to learn about it. So no your point is completely invalid and irrelevant to try and portray this as one story amongst many.

    And when you have different people talking from different centuries different aspects of the life of promised messiah then you are increasing this by a very significant amount. And you can run as much as you like away from this, in fact statistically speaking you have more chances in winning lottery 10 times in the role in the next 10 weeks then you could fudge or manipulate data like, place of birth, what tribe this is going to be from, and what household and predict his death like Isaiah 53 etc etc.

    Tildeb: If you are going to assume nothing, then why favour the assumption that we have insufficient data in order to support the best possible probability… in this case .5… that god either exists or does not? Seems to me you want it both ways. Platinga has fallen into what’s called the Monty Hall problem, which only seems to be correct by our intuition.

    Defend the Word: Assumption is only invoked when there are limited options given to you and reasonable amount of data, from which you could conclude that one option is as likely as the other. But going further then that, Christians believe that there is a greater probability then 50% but never the less it is part of our faith heritage.

    Tildeb: When faced with three doors behind which are a goat, a goat, and a fine new automobile, what is the probability of guessing the right door for the car? .33. Let’s say you choose Door Number One. Chances of being right? 1 in 3. Now (and this is the part Plantinga doesn’t understand) Monty opens up Door Number Two and reveals… a goat! The question he NOW asks is, do you want to switch your choice to Door Number Three? For those who don’t understand probabilities, it is intuitive to think your chances have now improved to 50-50, 1 in 2, P=.5. That’s false.

    Defend the Word: The example I give you was far more complex, and when looking at things starting out of nothing we know from the observable data that this does not happen. Big Bang testifies that we had beginning and that therefore due to the law of causality, we should have both cause and purpose, you are familiar with the laws of action and reaction to put it in the layman’s terms.
    So one is right to make assertion that probability of God being there increases significantly and if you try to invoke your multi universe theory then why not assume in the world where everything is possible and this universe just happens to be suitable for life why not have universe which could rightly support existence of God.
    And in which case why not assume the possibility that this is the universe that has God who may in fact be the one that was responsible for all other universes. You see atheists logic is very short sighted and often does not take into account all “scientific” data, often cornering themselves by their very own hypothesis.

    Tildeb: To explain why you should switch, let’s start with a thousand doors. Choose one, lets say Door Number One. Chances are 1 in a thousand. NOW Monty opens every door except Door Number Seven Hundred and Fifty-Six. Your chance do not increase to 50-50 but remain 1 in a thousand! The odds ARE 50-50 that Door Number Seven Hundred and Fifty-Six contains the automobile, in the same way that your odds remain in three that Door Number One hides the fine automobile in the original game but Door Number Three has a 50-50 possibility.

    The probability that there either is a god or is not a god presents us with the theoretical possibility of 50-50. But you don’t believe only half the time that god might exist. Belief is not a matter of strict probabilities nor does it empower authenticity of a suspension of belief for agnosticism. “I don’t know” is a cowardly cop-out. Using that formula, no one will know anything about anything and so the result is to never choose a door. But people DO choose doors in Monty Hall’s game the same way you choose to believe. Once that choice has been made, the probability is fixed only with that choice in the same way that the odds for choosing a particular door remains fixed. But other choices may have a much higher probability of being true, and this proper understanding of probabilities is ignored by Plantinga. Now that god has been shown to be absent from behind all the doors that have been opened by science, the probabilities of his existence are no better than 50-50 for the believer but approaching 1 for the non-believer.

    Defend the Word: What you are doing is building a straw man argument in order to tear him down. There is no such game, and facts that we have are very supportive of the probability in fact likelihood of God being there and witnessing this exchange of our ideas.

    Your last comment about science opening the doors and not finding God there is very typical of atheists, but not true in either philosophy of science or discoveries we have achieved in recent years. In fact your world view is known as “Scientism” which claims that the only truth that could be known is true science, yet when you consult the scientific community they will strongly deny such claim.

    Note that scientist themselves never make such claim this is a modern phenomenon that is unique to atheists. And in the same way you accuse agnostics of cowardly actions I would suggest that atheists distort, misunderstand and sometimes even give outright lie in order to defend their indefensible position.

    One does not have to be highly intelligent to spot massive holes in the logic of and atheist. Often going in circle, one only needs to analyse, exchanges between atheists and Christians and could easily see the pattern of behaviour that is full of avoidance, distortion, and factory with the production line of straw man and lack of readiness to consider arguments given by well reasoned faith. Note again I don’t pretend like atheists do that I have no faith, but I know that my faith is based on reason and logic, and unlike atheist I can say that I use to disbelieve but once I considered evidence I was able to weigh in the probabilities and conclude that my faith is reasonable.

  6. tildeb says:

    In fact your world view is known as “Scientism” which claims that the only truth that could be known is true science, yet when you consult the scientific community they will strongly deny such claim.

    No. The position I take, like all scientists when dealing with factual claims is that the material world that science can investigate is not only all that we can know but that it is all that there is to know about those claims. What defines science itself is called methodological naturalism, and anything outside this realm is by necessity outside the realm of science.

    All I am saying here is that Plantinga does not follow the math. When many factual claims in the bible are shown to be false – like revealing what is behind many doors in a game of Monty Hall – then the odds change. He has not taken this into consideration and he needs to. My beef with Plantinga is that he bases his argument on bad math.

  7. tildeb says:

    Another way to think about the central tenet of Plantinga’s position is about any claim whatsoever about anything. Let’s say someone tells you that you’ve just won a million pounds. The odds of that being true at the time you first here it is .5. The claim is either correct or incorrect. So do you believe it to be true? Nope. The first thing you do is attempt to inform the claim with evidence. Let’s say you do everything you can possibly do to find out if in fact, in actuality, in truth, whether or not the claim is true… and you find nothing. According to Plantinga, the probability of the claim being true are still as likely as the claim being false in spite of your rigorous attempt to ascertain independent verification, something more solid that someone telling you it’s true. Do you buy that reasoning that the probability remains just as likely true as just as likely false that you are a millionaire? I happen to think that one is silly to believe something in the absence of evidence no matter what the ‘something’ might be. More importantly, I think we can alter the probability of accuracy by keeping in mind that the absence of evidence can often be evidence of absence.

  8. tildeb says:

    Forgive the horrendous spelling and grammar mistakes. I was rushed and sloppy.

  9. No Problem I do it all the time, too.

  10. That is not what he is saying, secondly we touched upon the complexity of information and likewise when information simply is not too precise we simply have to use our faith even when we walk towards the further research in order to establish the truth. Likewise if information if even for a limited time is not going to be clear and it is going to be costing us dearly if we don’t make some kind of decision then we must act and often this will involve our past experiences and faith.

  11. It is very interesting that you only look at the “negative” and often disputed parts of the Bible yet you somehow omit to let the world know that there are many astonishingly accurate things in the Bible. Why is that? Secondly scepticism, disbelief and rejections are all incorporated into the Biblical texts so it is not a foreign concept to them. To therefore portray the Bible as some kind of “Believe” nonsense book is simply inaccurate and misleading. It should be therefore noted that based on better information one can fully agree with Prof Plantinga.

  12. misunderstoodranter says:

    “It is very interesting that you only look at the “negative” and often disputed parts of the Bible yet you somehow omit to let the world know that there are many astonishingly accurate things in the Bible.”

    Please give an example of what you mean….

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