Is the Weak Anthropic Principle Compatible With Divine Design?
A Response to Craig (1997)
The teleological argument, or argument from design, is considered by many to be one of the strongest arguments for the existence of god(s). Many proponents of this argument point to the improbability of a universe existing with properties compatible with the existence of observers as evidence that the universe was designed. This fine-tuning argument argues that the probability of the universe existing with the features compatible with our existence is prohibitively low and therefore necessitate a divine designer.
But is the improbability of the universe existing with compatible features evidence for divine design? Many scientists don’t think so. An alternative explanation can be found in the book The Anthropic Cosmological Principle . This book argues that even if there is a very high improbability of the universe existing with observers, the properties of the universe that allow us to exist are also what allow us to observe the universe with properties compatible with the existence of observers. If the universe did not have these properties, then we would not exist to observe the incompatible properties.
The idea that we must observe that the universe contains properties compatible with the existence of an observer because if it did not, no one would be here to observe it, is called the anthropic principle or the Weak Anthropic Principle (WAP). The WAP is significant in that it makes the improbability of any one universe (i.e. our own) irrelevant. We should expect that our universe has features compatible with our existence, since, after all, we exist.
In Barrow and Tipler on the Anthropic Principle vs. Divine Design, William Lane Craig attempts to rescue the teleogical argument from the deathblow of the WAP, which threatens to make the idea of a divine designer a gratuitous afterthought. Craig does not challenge the WAP per se, but attempts to make a sharp distinction between the WAP and the Anthropic Philosophy. Craig defines the Anthropic Philosophy as follows:
According to the Anthropic Philosophy, an attitude of surprise at the delicately balance features of the universe essential to life is inappropriate; we should expect the universe to look this way. While this does not explain the origin of those features, it shows no explanation is necessary. Hence to posit a divine Designer is gratuitous.
But does the Anthropic Philosophy logically follow from the WAP? This depends on what is meant by “surprise.” When is it appropriate to be surprised or amazed? Implicit in the idea of surprise is the unexpectedness of the event in question. Is an attitude of surprise appropriate with regard to the features of the universe? Craig concedes that::
3. We should not be surprised that we do not observe features of the universe which are incompatible with our own existence.
For if the features of the universe were incompatible with our existence, we should not be here to notice it. Hence, it is not surprising that we do not observe such features.
The reason for our nonsurprise, then, is the impossibility of our existence if incompatible features existed. So why is it that we do not observe incompatible features? Is it because incompatible features of the universe exist but we fail to observe them? No. The reason for our failure to observe them lies not in the failure of the observer to observe, but instead because they cannot exist. So (3) can be appropriately amended to read as follows:
3A. We should not be surprised that, given that we do observe features of the universe, the features that we observe are not incompatible with our own existence.
From this we derive:
4A. We should not be surprised that, given that we do observe features of the universe, the features that we observe are compatible with our own existence.
Craig contrasts (3) with the following statement:
But it follows neither from WAP nor (3) that:
4. We should not be surprised that we do observe features of the universe which are compatible with our existence.
Clearly, (3) and (4) lack the precision of (3A) and (4A). It is this lack of precision that Craig seeks to exploit. It is true that (4) does not logically follow from (3). But this is only because there is nothing in (3) that implies that we have made any observations at all. His comments suggest that this is what he means, but both his analysis and his schematics ignore that we have. If Craig was making the point that our failure to observe ~A does not imply A, he would be quite correct. But Craig is attempting to show something quite different. He is trying to show that our failure to observe ~A is because ~A is impossible. If it can be shown that ~A is impossible, A is proven. Craig’s denial of (4), then, is clearly unwarranted.
Craig, however, attempts to show that (4) is not implied by (3) or the WAP. (As we have seen, (3) does not imply (4), but only because (3) lacks precision.)
For although the object of surprise in (4) might at first blush appear to be simply the contrapositive of the object of surprise in (3), this is mistaken. This can be clearly seen by means of an illustration (borrowed from John Leslie): suppose you are dragged before a firing squad of 100 trained marksmen, all of them with rifles aimed at your heart, to be executed. The command is given; you hear the deafening sound of the guns. And you observe that you are still alive, that all of the 100 marksmen missed! Now while it is true that
5. You should not be surprised that you do not observe that you are dead,
nonetheless it is equally true that
6. You should be surprised that you do observe that you are alive.
Since the firing squad’s missing you altogether is extremely improbable, the surprise expressed in (6) is wholly appropriate, though you are not surprised that you do not observe that you are dead, since if you were dead you could not observe it.
Again, Craig is attempting to exploit a lack of precision. Is the failure to observe that you are dead caused because we are dead but simply failed to observe it? Obviously this is not his intent, but there is nothing in (5) that explicitly denies that this is a possibility. So (5) should be amended to read:
5A. You should not be surprised that, given that you observe your aliveness, you do observe that you are not dead.
Since “not dead” and “alive” are equivalent, it is trivial to use textual substitution to arrive at:
5B. You should not be surprised that, given that you observe your aliveness, you do observe that you are alive.
Clearly, (5A) and (5B) are logically identical pairs. But what to make of (6)? Surely we are justified in our surprise given the unexpectedness of our continued existence. But (6) states that you should be surprised that you observe that you are alive, not that you are alive. If (5) obtains because “if you were dead you could not observe it,” then given that you observe your aliveness, (6) cannot obtain because it is impossible to observe yourself in any other condition but alive.
Based on his fallacious example, Craig comments:
Similarly, while we should not be surprised that we do not observe features of the universe which are incompatible with our existence, it is nevertheless true that
7. We should be surprised that we do observe features of the universe which are compatible with our existence,
(7) is simply the negation of (4). Since (4) logically follows from (3A), which more accurately represents what Craig was attempting to express in (3), (7) cannot obtain if (3), rightly interpreted, does. So Craig fails in his attempt to decouple the WAP from the Anthropic Philosophy he categorizes as antagonistic to the teleological argument.
Although it has been shown that (3) and (7) are incompatible, it is possible to argue against the Anthropic philosophy by arguing against the WAP. This is exactly what Craig unintentionally proposes when he posits:
7*. We should be surprised that we do observe basic features of the universe which individually or collectively are excessively improbable and are necessary conditions of our own existence.
Since (7*) was proposed as an extension of (7), there is no basis for accepting its validity in view of the fact that (3) and (7) are contradictories. But what if Craig chooses to jettison (3) in favor of (7) and by extension (7*)? Craig can support a modified version of (7*) by emphasing the improbability of the universe with compatible basic features. But how improbable is excessively improbable? This is dependent upon how many possible universes exist. Regardless of how low the probability is that a universe with such properties could exist, if it can be shown that the universe has a non-zero probability of existing, then there is no reason to claim that the basic feature are excessively improbable.
Craig poses the following question:
The fundamental assumption behind the Anthropic philosopher’s reasoning in this regard seems to be something along the lines of
8. If the Universe contains an exhaustively random and infinite number of universes, then anything that can occur with non-vanishing probability will occur somewhere.
But why should we think that the number of universes is actually infinite?
If the number of universes is equal to or greater than the inverse of the probability of the universe existing with the necessary conditions for observers, then it is probable that at least one universe with such properties exists. It is not necessary to prove that the actual range of universes is infinite. Since this is the case, the question may be presented to Craig: why should we think that the number of universes is significantly less than the inverse of the probability? Craig may wish to argue that the number of universes would have to be excessively large. But on what basis do we have for calling any number excessive? Even if the actual range of universes is less than infinite, there is no reason to believe that the range is smaller than the number to make at least one universe with observers probable.
Craig again appeals to improbability in his third footnote:
What unprejudiced and right-minded person could possibly regard a chimpanzee’s haphazardly typing out the complete plays and sonnets of Shakespeare as equally probable with any chaotic series of letters?
Actually, if the chances of typing any letter on a keyboard is equal, then the chances that a chimpanzee typing all of Shakespeare and any one particular sequence of of letters equal in length to the works of Shakespeare (specified in advance) are equal. Craig continues:
The objection fails to reckon with the difference between randomness, order, and complexity. On the first level of randomness, there is a non- denumerably infinite number of chaotic sequences, e.g., ‘adfzwj,’ each of which is equally improbable and which collectively could serve to exhaust all sequences typed by the ape. But the meta-level of ordered letters, e.g., ,’crystalcrystalcrystal ,’ need never be produced by his random efforts, were he to type for eternity.
His statement regarding the ordered sequence ‘crystalcrystalcrystal’ is clearly mistaken. Given that the chance of typing any key on the keyboard is 1 in 26, then the odds of typing any particular sequence of letters is equal to 1:26^L (one in 26 raised to the Lth power), where ^ means ‘raised to the power of’ and L is the length of the sequence. Interestingly, if the ape were to type for eternity, it is not only probable that the sequence would be produced, it would actually be produced an infinite number of times. But in reality, it is not necessary for the ape to type for eternity. Given that the ape types 26^L copies of random sequences, it is probable that one of the sequences would be the desired result.
Even more improbable is the metameta-level of complexity, in which information is supplied, e.g., ‘To be or not to be, that is the question.’ Hence, it is fallacious to assert that since some set of conditions must obtain in the universe, the actual set is in no way improbable or in need of explanation.
Again, Craig is mistaken. Since the sequence of letters is longer in the phrase ‘To be…’ and since this sequence also includes capital letters and punctuation, the odds of any one sequence being produced is considerably less, but even though the phrase would be produced much less frequently than the much simpler ‘crystalcrystalcrystal,’ it is also true that if our immortal ape continued endlessly pounding at the keyboard, he would also produce this sequence an infinite number of times. But just like it is not necessary for the ape to type for eternity to produce the ‘crystalcrystalcrystal,’ the probability of any phrase, even as complex as a Shakesperean sonnet or play, can be calculated and does not require an actual infinite.
The teleological argument traditionally draws its strength from the improbability of the universe containing features compatible with our existence. The effect of the WAP is to make the improbability of any one universe (i.e. our own) irrelevant. Craig presents a false dilemna when he comments:
We appear then to be confronted with two alternatives: posit either a cosmic Designer or an exhaustively random, infinite number of other worlds. Faced with these options, is not theism not just as rational a choice as multiple worlds?
But, as I have shown, it is not necessary to prove that there be an infinite number of other worlds. For the teleological argument to have any significance on probabilistic grounds, the proponent of the argument must provide some evidence that the actual number of universes is much less than the number of universes necessary to make the existence of a universe with observers probable. The WAP makes it clear that the mere improbability of our own universe is not evidence for divine design. Without evidence for divine design, there is no rational basis for belief in a designer.
 William Lane Craig, “Barrow and Tipler on the Anthropic Principle vs. Divine Design” (<URL:http://www.leaderu.com/offices/billcraig/docs/barrow.html>, 1997)
“Is the Weak Anthropic Principle Compatible With Divine Design?” is copyright © 1997 by Kyle Kelly. All rights reserved.
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