Design Arguments Arguments for theism • Ontological arguments • Cosmological arguments • Design arguments Ontological arguments • Attempt to establish the existence of God a priori (not based on any facts known by experience) • It follows from the very idea of a theistic god that such a being must exist • A theistic god by definition has all perfections • Existence is a perfection • Thus, a theistic god exists Cosmological arguments • Attempt to show that the very existence of the cosmos—any cosmos--must be explained by saying that it was created by a supernatural being • It doesn’t matter what the cosmos is like; it must have a divine origin Design arguments • The world has some special feature that is best explained by supposing that it was designed that way by a rational being. • This feature cannot have been designed by any inhabitant of the cosmos. • It’s reasonable to accept the best explanation for something known to be the case. • So it is reasonable to conclude that there is a supernatural being who designed the cosmos. • Also called ‘teleological arguments’, since they appeal to purposes or goals The central premise • The cosmos has some special feature that is best explained as the product of intelligent design by some sort of god. • Some possible universes show evidence of intelligent design and others don’t. • What sort of feature would count as evidence of intelligent design? length: 7.890348761229cm width: 3.980012563422cm height: 4.39976130025cm mass: 1.082230076113kg The Question Can we find any objects or features of the world that appear to have been designed, but were not designed by human beings or other inhabitants of the cosmos? Why are there living organisms? 1. They were designed by an intelligent nonorganism: a supernatural being 2. Or maybe they came about by some natural process involving evolution by natural selection. • Organisms are born with random variations. • Some of these variations are advantageous. • Those organisms that have these traits are more likely to reproduce. • Their offspring inherit the advantageous traits. What evolution by natural selection doesn’t explain • • • • Where did the first organisms come from? Why is the universe conducive to life? It didn’t have to be that way. That the universe is conducive to life is very surprising. The gravitational constant G = 6.67384 x 10-11 N(m/kg)2 Other numbers ‘filled in by hand’: the masses of the proton and neutron, the charge on the electron, the strength of the electromagnetic force, and many more What would the universe be like if these numbers were different? • If they were even slightly different—in some cases by one part in 1055--life would be impossible. • There would be no atoms, or no stars, or only very short-lived stars,… A universe-making machine The pointer on dial 18 reads .0082301766. If it were not set at a value between .0082301761 and .0082301768, there would be no carbon atoms and hence no life. The pointer on dial 12 reads 629.089271, and the pointer on dial 4 reads 629.089268. If the difference between these readings were greater than .000005, all stars would burn out within a few thousand years; if they were exactly equal, there would be no matter but only radiation. The proportion of possible universes (with the same general laws as ours) that contain stars has been estimated at 1 in 10229. Why are the dials set so as to make life possible? • By design: Some rational being set the dials as they are in order to create a universe containing life • Why would a rational being want to create a universe with life in it? • We don’t need to answer this question in order to know that the cosmos was designed. The fine-tuning argument 1. The best explanation of the fact that the universe is hospitable to life (if not the only explanation) is that it was designed that way by a supernatural being 2. It’s reasonable to accept the best explanation for something we know to have occurred. 3. So we should conclude that the universe was designed by a supernatural being. The fine-tuning argument: three questions 1. Does the fact that the universe is hospitable to life need any explanation at all? 2. Is the design hypothesis a good explanation of that fact? 3. Is there another explanation equally good? 1. Does the fact need any explanation? • The dials just happen to be set as they are by chance. • That may be unlikely, but unlikely things do happen. • The dials had to be set somehow, and their actual settings are is no less likely than any other settings. • We were just lucky. 2. Is the design explanation a good one? • It doesn’t explain the existence of the Designer (Mackie). • It doesn’t explain the existence of organized complexity (Dawkins). • Both points are correct, but irrelevant. • Even if the design hypothesis does not explain the existence of organized complexity, it might explain why the universe is conducive to life. • Any explanation of a contingent fact will appeal to something else that it doesn’t explain. • The hypothesis that the Martian watch was dropped by the Americans leaves many facts unexplained. 3. Is there any other explanation? • The machine had to be fine-tuned for life, because otherwise there wouldn’t be anyone here to ask any questions. So no further explanation is needed. • There had to be a working watch lying in the Martian sand, because otherwise you wouldn’t have found one there. So no further explanation is needed. • The fact that you found a watch shows that there is one there, but not why there is. • The fact that there is life in the universe shows that the machine is fine-tuned for life, but not why it is. Is there any other explanation? • The numbers had to be the way they are. • The possible universes where the numbers are incompatible with life are not really possible. • The dials could not have been set in a way that produced a universe with no stars, or where all matter is violently radioactive,… • But there is no reason to believe this, and on present evidence it looks very unlikely. The ‘multiverse’ hypothesis • Our universe is one of many actual, concrete universes. • In every universe the numbers are different. • The machine’s dials are set and reset at random many times, and each time it produces another universe • There are so many different universes that it’s likely that at least one will be life-permitting. • It’s not surprising that that’s the universe we live in, since there are no philosophers in any of the others. The ‘multiverse’ Fishing • You catch a fish 9.24102 inches long. • No surprise: every fish has some length, and there’s nothing special about that one. • But your fishing gear can only catch fish that are 9.24102 inches long ± one part in a million. Why did you catch a fish 9.24102 inches long? 1. Someone knew about your fishing gear, and put a fish of that length in the lake for you to catch: a design explanation. 2. There are millions of fish of different lengths in the lake, so many that one of them is bound to be 9.24102 inches long: analogous to the ‘multiverse’ explanation. • It’s no surprise that you caught that one, since it's the only one you can catch. 3. There is only one fish in the lake, and by good luck it just happened to be 9.24102 inches long: no explanation. Now what? • It’s reasonable, at least, to accept the best available explanation of something we know to be the case. • Suppose the design hypothesis and the ‘multiverse’ are both good explanations of why the universe is life-permitting, and there are no other good explanations. • Which explanation is better? Which explanation is better? • The ‘multiverse’ explanation is extravagant. • There are not merely many possible universes. • There are trillions of actual, concrete universes. • For some reason we are able to observe only one. • It may not be a proper scientific hypothesis. Which explanation is better? • The design explanation is equally extravagant, even if it doesn’t specify the precise nature of the Designer. • It appeals to a supernatural being, which for some reason we are unable to observe. • It’s no more ‘scientific’ than the multiverse hypothesis. Which explanation is better? • Some say the design hypothesis is simpler, as it posits only one object rather than trillions (Swinburne). • Others say the ‘multiverse’ hypothesis is simpler, since it posits only objects of the same sort that we already know to exist. • Both are extravagant, but in different ways. Tentative conclusion • Suppose the ‘multiverse’ hypothesis is a good explanation of why the universe (or some universe) is life-permitting. • It’s not obviously a worse explanation than the design hypothesis • Then the design argument is inconclusive. • At best it shows this: either there is a supernatural designer, or there are many other universes.