The Teleological argument is based on the findings of cosmologists over the past 40 years, that if a number of laws or universal constants had been a little different, the universe would not support life, and may not even exist at all by now. The scientific facts on which these conclusions are based are outlined in Science and the design of the universe. Here we look at the formal philosophical argument and the objections made to it.
The word 'universe' is used in two slightly different ways - it can mean the space-time that we live in, which began at the big bang (I will call this 'our universe'), or all space-time, matter and energy that has existed, which may be more than our universe (I will call this 'the universe' or the 'multiverse'). It is possible that the universe/multiverse consists of a series of universes leading up to our universe, or many universes existing in parallel; equally it is possible that 'our universe' is all there is and it and 'the universe' are one and the same. (Note that some of the quotes say "the universe" when, in these terms, they mean "our universe".)
God, if he exists, is not physical, and would be outside the universe, outside of space and time.
Premise 1 is obvious and uncontroversial, but the remaining premises require justification.
Premise 2 is the conclusion of most cosmologists. For example Martin Rees, one of the world's most respected cosmologists, and John Gribbon write in 'Cosmic Coincidences':
If we modify the value of one of the fundamental constants, something invariably goes wrong, leading to a universe that is inhospitable to life as we know it ...The conditions in our universe really do seem to be uniquely suitable for life forms like ourselves.
Paul Davies says:
There is now broad agreement among physicists and cosmologists that the universe is in several respects 'fine-tuned' for life ... [or] rather it is fine-tuned for the building blocks and environments that life requires.
Premise 3 is simply a statement of the possibilities. It is difficult to find any others. The logic is this: Either our universe could have been any different or it couldn't (physical necessity). If it could have been different, it took this form either because it was designed or not designed (chance).
Premise 4 is the same as saying there is an underlying physical "law" that determines the characteristics of our universe - sometimes called a 'Theory of Everything' (ToE). However we can say of a ToE:
Does string theory predict the state of the universe? The answer is that it does not.In other words, string theory does not provide the physical necessity for the universal fine-tuning.
Thus Paul Davies concludes: It seems, then, that the physical universe does not have to be the way it is; it could have been otherwise.
and Lee Smolin says: It strains credulity to imagine that mathematical consistency could be the soul reason for the parameters.
Premise 5 is considered to be virtually impossible by almost all cosmologists - the fineness of the tuning is immensely improbable by chance. The following quotes from eminent cosmologists show this:
To make the first 119 decimal places of the vacuum energy zero is most certainly no accident.
Leonard Susskind ('The Cosmic Landscape')
Perhaps before going further we should ask just how probable is it that a universe created by randomly choosing the parameters will contain stars. Given what we have already said, it is simple to estimate this probability. For those readers who are interested, the arithmetic is in the notes. The answer, in round numbers, comes to about one chance in 10^229.
Lee Smolin ('Life of the Cosmos')
This now tells us how precise the Creator's aim must have been: namely to an accuracy of one part in 10^10^123. This is an extraordinary figure.
Roger Penrose, former Professor of Mathematics at Oxford University and a cosmologist who worked with Stephen Hawking ('The Emperor's New Mind')
Conclusion (proposition 6): The argument is logically valid and its premises seem more probably true than false. Thus it leads to the probable conclusion that our universe was designed. The argument stops there, but, when combined with other arguments, it is reasonable to conclude that the only possible designer is God.
Not surprisingly, there are many objections to the argument.
Premise 2:
Physicist Victor Stenger has constructed a computer model that shows that about half the possible universes would exist long enough to allow stars and planets to form. However the model is very simplistic (it doesn't account for more than a few of the required parameters) and his conclusions are in direct contradiction with Rees, Davies, Penrose and Smolin, and he doesn't seem to have convinced any cosmologists.
Stenger has also argued that this conclusion is based on the assumption that life must be carbon-based as on earth. But small changes to some of the constants make it unlikely even that stars or planets would form, or that any atoms other than hydrogen or perhaps helium (which are not enough to make anything nearly as complex as life) would form, or even that our universe would last long enough to allow life to form. Again, Stenger doesn't seem to have convinced many cosmologists of his arguments here.
Premise 3:
The most common scientific explanation of the fine-tuning is the multiverse hypothesis - that our universe is part of a much larger universe (often called a multiverse) which has generated a large number of universes. If there were enough of these alternative universes, and if each one had different settings of the laws and constants, then eventually an inhabitable universe would be created and that is the one we find ourselves in. Outlandish as this idea might appear at first, cosmologists believe it is consistent with current cosmological theory, even though other universes could never be observed.
However the multiverse hypothesis doesn't appear to be sufficent to throw doubt on Premise 3, for the following reasons:
So it appears the same three possibilities remain even if the multiverse is considered to be possible.
Premise 4
It remains possible that science will one day find an underlying reason or law which makes the characteristics of our universe inevitable. Despite the fact that we don't have this now, that some cosmologists doubt we ever will, and that it is hard to see how the 'nothing' out of which our universe appeared could have contained any laws, this remains a possibility. Whether it could be considered a probability is more a matter of faith or personal preference than of science. But it is interesting that the current interest of cosmologists in the multiverse throws this objection into serious doubt, because they all assume that each universe within the multiverse has different settings, and so are not fixed by physical necessity at all.
Premise 5
Perhaps the most common objections to the design argument are based on probability. How do we know that all of the possible settings are equally likely? How do we know the settings in our universe are statistically independent? But these and other similar objections lose their weight when we consider the enormity of Roger Penrose's estimate of overall probalility.
More fundamental is the argument that it is meaningless to talk about probability when we only have one known universe and no frequncy distribution of universe on which to make a judgment of probability. But this objection also seems to founder on the rock of the conclusions of cosmologists.
The multiverse doesn't help with the probability objection either. Currently string theory predicts that, if there is a multiverse, there would be 10^500 universes. This is an enormously large number, but only an infinitessimal fraction of Penrose's estimate of probability. Even 10^500 universes don't make our universe even remotely likely by chance.
Conclusion (proposition 6)
There are objections to the form of the conclusion also.
There also seem to be a collection of erroneous or unjustfied objections to the design argument. For example:
Thus these 'objections' tend to strengthen rather than weaken the design argument because they seem rather desperate attmepts to find something to disagree with, and hence tacit admittals that the argument is strong.
This seems like a strong argument. It has a common sense feel about it, and the objections do not. The only objection which seems to have any weight at all is the thought that perhaps one day we will find an underlying physical cause. I haven't found many cosmologists who seem comfortable with this, and it remains true that at the present time we have nothing which could supply such a cause.
The multiverse, which is the favoured scientific explanation, really doesn't change the argument as formulated here. The probability of it all happening by chance remains vanishingly small, and there is no hypothesis of physical necessity on the horizon.
The designer hypothesis isn't competing with any scientific hypothesis such as the multiverse. This form of the argument simply requires any scientific hypothesis to be tested against the three possibilities of necessity, chance or design. So far, design seems to be by far the most probable.
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