Over at The Skeptical Zone, Dr. Elizabeth Liddle has written an interesting essay, titled, Proof: Why naturalist science can be no threat to faith in God, in which she argues that even if scientists were to discover that the appearance of complex life was inevitable, with or without an interventionist God, that discovery should not dent people’s religious faith in the slightest degree: “finding out that life is perfectly possible in the absence of an interventionist God tells absolutely nothing at all about whether God exists.” Dr. Liddle’s essay is cleverly argued and thought-provoking; however, I believe it is marred by several serious flaws.
Framing the question properly
In the opening paragraph of her essay, Dr. Liddle frames the question of God’s existence in terms of whether you believe in a God who intervenes in Nature. She writes:
I will represent the hypothesis that (a non-Deist, i.e. an interventionist) God exists as HG, and the evidence of complex life as LC. What we want to know is the posterior probability that HG is true, given LC, written
P(HG|LN)
which, in English, is: the probability that God exists, given the evidence before us of complex life.
I’d like to make a few remarks here. First, I rather dislike the term “intervention,” as it implicitly assumes that God would be absent from His creation if He didn’t intervene in it – which is clearly false, if He maintains the whole of creation in being. Nevertheless, I would have to describe myself as an “interventionist,” if pressed; the arguments of Dr. Rob Sheldon and Dr. Branko Kozulic have convinced me that “front-loading” cannot explain life on Earth today, in all its diversity.
Second, the term “Deism” is popularly construed as the view that not only does God not interfere with the functioning of the natural world in any way, but also that each human being’s relationship with God is impersonal: while the laws of Nature are designed for the general well-being of humanity, God does not actively intervene in the affairs of any particular individual. But the point I’d like to make here is that someone could still have a personal relationship with God, even if they believed that He never intervened in Nature. Such a person might believe, for instance, that God designed the world in anticipation of the personal needs of each human individual who was to be born, in such a way that providential events would occur in each person’s life at times when they were required. Indeed, a person holding to such a view would have much more in common with a believer in revealed religion than with someone who held that God was impersonal. For the question of how God attends to our personal needs is logically secondary to the question of whether He does so.
Third, Dr. Liddle displays an extraordinary lack of precision throughout her essay, when stating her hypothesis HG, which is that an interventionist God exists. The negation of this hypothesis, or not-HG, is simply the hypothesis that there is no interventionist God. Yet throughout her essay, Dr. Liddle abbreviates her hypothesis HG to the bare statement that “God exists,” the negation of which is that “God does not exist.” But there is a world of theological difference between “God does not exist” and “God exists, but He is not an interventionist.”
Fourth, the relevant evidence E is not merely “complex life”: after all, random noise is also complex. What Dr. Liddle should have said was: “life containing a high degree of functional complex specified information” – or, if she dislikes Intelligent Design jargon, “life containing complex structures whose function can be briefly described, and which are functional only for a tiny fraction of all possible arrangements of their components.” (For 100-amino acid proteins, for instance, this fraction is estimated to be around 1 in 1065.)
Finally, I presume Dr. Liddle is well aware that Intelligent Design theory makes no assumptions whatsoever regarding an interventionist God. Even though many ID theorists (including myself) happen to believe in an “interventionist” Deity, the main argument of Intelligent Design theory can be summarized as follows: (1) the evolutionary process is incapable of creating new biological information to any significant degree; (2) moreover, even if the information required to produce life were already embedded within Nature itself (e.g. as a feature of fitness landscapes), materialism would still be incapable of explaining this striking fact; (3) on the other hand, the creation of new information is a hallmark of intelligent agency; hence, (4) the information required to produce life in all its diversity is best explained by positing an intelligent source. (Whether this intelligent source input the requisite information at the Big Bang or at some subsequent point is of no consequence here.) Or as Professor William Dembski puts it in his essay, Conservation of Information Made Simple:
If blind material forces can only redistribute existing information, then where does the information that allows for successful search, whether in biological evolution or in evolutionary computing or in cosmological fine-tuning or wherever, come from in the first place? The answer will by now be obvious: from intelligence.
I therefore find it puzzling that Dr. Liddle writes:
If IDists can show that the probability of complex life, given no God, is sufficiently tiny that it effectively cannot occur within the lifetime of the universe, that second term on the denominator will go to zero, and God becomes a certainty!
Dr. Liddle should know that Intelligent Design theorists do not attempt to compute “the probability of complex life, given no God.” Rather, what they try to calculate is the probability of complex life evolving, from an initial set of conditions where the quantity of functional complex specified information (on Earth, or in the cosmos) is zero. Finding that probability to practically indistinguishable from zero, ID theorists opt for a more reasonable explanation for the origin of the functional complex specified information we find in living things: and the best explanation is that life on Earth today is the product of an Intelligent Agent. However, the inference that this Intelligent Agent is God goes beyond what Intelligent Design theory can tell us.
Dr. Liddle’s Bayesian argument
Dr. Liddle next proceeds to argue, along Bayesian lines, for the view that even the scientific discovery that the emergence of complex life is inevitable, given the laws of Nature, should not weaken people’s religious faith.
She states:
By Bayes rule:
P(HG|LC) =
P(LC|HG)*P(HG) P(LC|HG)*P(HG) + P(LC|not-HG)*P(not-HG)
Where
P(LC|HG) is the probability of complex life, given that God exists,
P(HG), is our prior belief that God exists, expressed as a probability,
P(LC|not-HG) is the probability of complex life, given that God does not exist, and
P(not-HG) is the probability that God does not exist (which equals 1-P(HG).
I find it very disappointing that Dr. Liddle once again mis-states HG as the hypothesis that “God exists,” when it should be: “an interventionist God exists.” Similarly, she mis-states not-HG as the hypothesis that “God does not exist,” when it should be: “an interventionist God does not exist.” Deism is a very different thing from atheism.
But let us continue. Dr. Liddle notes, correctly, that “the term on the numerator is identical to the first term in the denominator.” This is a significant fact. What it means is that our assessment of the likelihood of an interventionist God’s existence, given the existence of complex life, will depend on how big the second term in the denominator is (i.e. P(LC|not-HG)*P(not-HG)), compared to the first term (i.e. P(LC|HG)*P(HG)).
Dr. Liddle then sets the likelihood of complex life existing, given the existence of an interventionist God, to exactly 1, “as it seems just weird to posit an interventionist God who doesn’t make complex life.” In mathematical terminology, she is arguing that P(LC|HG) = 1. On this point, I would agree with her.
The interesting twist in Dr. Liddle’s argument occurs when she supposes, purely for argument’s sake, scientists one day manage to demonstrate that the likelihood of complex life existing, even in the absence of an interventionist God, is also exactly 1. (In other words, P(LC|not-HG) = 1.) What follows then? We can simplify the Bayesian formula as follows:
|
P(HG|LC) = |
P(LC|HG)*P(HG) |
|
P(LC|HG)*P(HG) + P(LC|not-HG)*P(not-HG) |
|
|
= |
P(HG) |
|
P(HG) + P(not-HG) |
|
|
= |
P(HG) |
|
1 |
which is simply P(HG). In other words, Dr. Liddle argues, even the discovery that complex life is inevitable, with or without an interventionist God, should not weaken anyone’s faith, as it will make no difference to their prior belief that God exists (i.e. the probability P(HG)). Ergo, naturalistic science poses no threat to religious faith. QED?
What the argument gets right
Not quite. Dr. Liddle is right on one vital point: for those people who are absolutely certain of God’s existence on independent grounds, the discovery that the appearance of complex life was naturally inevitable would in no way diminish their faith in God. Or as Dr. Liddle puts it: “If your faith is absolute, absolute it will remain.” In my post, Does scientific knowledge presuppose God? A reply to Carroll, Coyne, Dawkins and Loftus (November 23, 2013), I presented what I believe is a powerful transcendental argument for the existence of God, based on the mere possibility of our doing science at all. In my next post, Is God a good theory? A response to Sean Carroll (Part One), I argued that there were several kinds of rational certainty, and defended the view that arguments could be mounted for the rational certainty of God’s existence. In the following post, Is God a good theory? A response to Sean Carroll (Part Two), I defended the cosmological fine-tuning argument’s claim to establish the existence of a God Who not only wants to make a universe containing intelligent beings, but Who also wants those beings to be aware of His existence.
These arguments do not yet take us to an interventionist God, however. To get to that conclusion, one might invoke the argument from the irreducibility of mind to matter (as Alfred Russel Wallace did); or one might argue for the need for a grand cosmic order in which virtue is eventually rewarded and vice eventually punished, in order to explain the existence of objective moral norms. The first argument points to at least two interventions in the history of the cosmos – namely, the appearance of sentience and sapience, respectively – while the second argument points to the need for a future intervention. These arguments are logically independent of any scientific discoveries regarding the likelihood of complex life emerging with or without Divine intervention. Hence if one already accepts such arguments as certain, it does not matter whether this likelihood is low or high; one’s faith in an interventionist Deity will be unaffected.
The flaws in Dr. Liddle’s Bayesian argument
However, Dr. Liddle’s claim that naturalistic science poses no threat to religious faith is mistaken on three counts.
First, she confuses epistemic priority with chronological priority – as if people go through some initial phase when they believe in God for reasons that have nothing to do with design, then hear about the biological design argument for God’s existence, and finally learn that this particular argument doesn’t work. For instance, she states that if scientists one day show that the emergence of life is inevitable even without an interventionist God, “the denominator simply sums to unity, leaving our belief in God exactly where it started” (italics mine). But what normally happens is that from the beginning, the biological design argument is presented to young children as a powerful argument for God’s existence, when these children are first told that God made everything. Whether it be the design of the eye, or of a bird’s feather, or a tiger’s stripes, or a butterfly’s wings, the argument is an intellectually formative one for most children who are brought up to believe in God. Hence, if someone were to be convinced that the biological design argument is a faulty argument for God’s existence, there could be no question of them going back to their prior position, as they never had one: the argument is, and always has been, part of the very warp and woof of their reasons for believing in God.
Second, in real life, it is rare for people to be certain of God’s existence, solely on the basis of a single argument. Usually, people’s belief in God is buttressed by several supporting arguments; hence we can meaningfully ask how strong someone’s faith in God would be, if one of these arguments were undermined. But if the biological design argument were someone’s principal reason for believing in an “interventionist” God – as it might well be, for someone who didn’t pray very often and who was not particularly religious – then if that person were mistakenly persuaded (say, by reading Richard Dawkins’ books) that this argument was false, they would be in real danger of losing their faith altogether, unless they could find an intellectually tenable “fallback” position (e.g. the view that God was at least responsible for the emergence of sentient and sapient beings, and that He will intervene in the world at some future date, even if He does not do so currently). On the other hand, someone who (a) was in the habit of praying regularly and obtaining answers to their prayers, or (b) accepted the claims of a particular religion because they thought there was good evidence for these claims would be in a more fortunate position, as they would have stronger reasons for believing in a God Who intervenes in human affairs.
Third, it should be pointed out that the classical theistic arguments for God’s existence make no attempt to establish the existence of an “interventionist” God, or even a personal Deity. The Anselmian ontological argument (which has few fans nowadays) certainly doesn’t; neither does the First Cause argument, or the argument for a Necessary Being, or for an Intelligence ordering all things towards their ends. Even the arguments I listed above (the transcendental argument and the cosmological design argument) simply attempt to show that there is a God Who wants His existence to be known by us. That conclusion could be considered as an argument for a personal Deity, but it’s a rather thin one. And we haven’t established anything about the likelihood of Divine intervention in the history of the universe. On the other hand, the biological design argument for God’s existence (which goes beyond the claims of Intelligent Design theory) has some bearing on the question of God’s intervention in the history of the world.
Apart from the biological design argument, the remaining arguments for Divine intervention in history (which are different from the arguments traditionally associated with classical theism) can be enumerated as follows:
(a) the argument from the irreducibility of mind to matter, which requires God to have intervened in order to bring about the emergence of sentient and (later on) sapient beings;
(b) the moral argument for God’s existence, which requires God to “put things right” at some date in the future, and establish a rule of justice in the cosmos, where virtue is rewarded and vice is punished;
(c) evidential arguments for the truth of this or that religion (e.g. the kuzari argument, or arguments based on miracles);
(d) the argument from the experience of having one’s petitionary prayers answered; and
(e) arguments based on subjective religious experience.
The deleterious impact of Darwinism on religious faith after 1859
These are powerfully persuasive arguments for many people, and Dr. Liddle is correct when she asserts that a religious person’s faith in an interventionist God need not be harmed by the discovery that a naturalistic account can be given of the origin of complex life. But there is an ocean of difference between “need not” and “will not.” Real tensions would arise, for instance, if the particular religion that one believed in were to declare that God intervened so as to bring (some, or all) life-forms into existence, and scientists were to show that no intervention was necessary. Indeed, the testimony of history amply refutes Dr. Liddle’s contention that people’s faith in an interventionist God should not be harmed if scientists discovered that no Divine intervention was necessary to bring about life on Earth, in all its diversity. In the mid-nineteenth century, many Victorians who were convinced by Darwin’s arguments suffered a real crisis of faith. The scientist H. G. Wells chronicled the impact of the clash of worldviews between Darwinism and traditional Christianity that occurred with the publication of Darwin’s Origin of Species in 1859, in his Outline of History:
Many men and women are still living who can remember the dismay and distress among ordinary intelligent people in the Western communities as the invincible case of the biologists and geologists against the orthodox Christian cosmogony unfolded itself…
The immediate effect of this great dispute upon the ideas and methods of people in the prosperous and influential classes throughout the westernized world was very detrimental indeed. The new biological science was bringing nothing constructive as yet to replace the old moral stand-bys. A real de-moralization ensued. The general level of social life in those classes was far higher in the early twentieth than in the early seventeenth century, but in one respect, in respect to disinterestedness and conscientiousness in these classes, it is probable that the tone of the earlier age was better than the latter. In the owning and active classes of the seventeenth century, in spite of a few definite infidels, there was probably a much higher percentage of men and women who prayed sincerely, who searched their souls to find if they had done evil, and who were prepared to suffer and make great sacrifices for what they conceived to be right, than in the opening years of the twentieth century. There was a real loss of faith after 1859. The true gold of religion was in many cases thrown away with the worn-out purse that had contained it for so long, and it was not recovered. Towards the close of the nineteenth century a crude misunderstanding of Darwinism had become the fundamental mindstuff of great masses of the educated everywhere. The seventeenth-century kings and owners and rulers and leaders had had the idea at the back of their minds that they prevailed by the will of God; they really feared him, they got priests to put things right for them with him; when they were wicked, they tried not to think of him. But the old faith of the kings, owners and rulers of the opening twentieth century had faded under the actinic light of scientific criticism. Prevalent peoples at the close of the nineteenth century believed that they prevailed by virtue of the Struggle for Existence, in which the strong and cunning get the better of the weak and confiding. And they believed further that they had to be strong, energetic, ruthless, practical, egotistical, because God was dead, and had always, it seemed, been dead which was going altogether further than the new knowledge justified. (Garden City Publishing Co. Inc., Garden City, New York, 1920, pp. 439-440)
Was this an irrational reaction, given the widespread public acceptance of Darwinism? Not entirely. The tension between Darwinism (which said that our mental capacities are the product of a long slow process of ascent from “lower” life-forms) and Genesis (which said that we fell from our God-given position as the stewards of creation and experienced a subsequent weakening of the will and darkening of the intellect) was a palpable one. Again, a straightforward reading of Genesis seems to suggest that God repeatedly intervened in bringing about the production of the various life-forms we find on Earth today. Hence a scientific demonstration that no intervention was necessary in order to generate complex life would naturally tend to weaken many people’s faith in a religion that was based on the Bible, even if such a demonstration did not logically necessitate that God never intervenes in human history. Of course, many Jews and Christians have since arrived at their own ways of resolving the tension between science and Genesis. However, I find it astonishing that Dr. Liddle glides over this tension and the detrimental effect it can have on religious faith in her essay.
The question Dr. Liddle should have asked
I’d like to conclude by suggesting that Dr. Liddle’s essay would have hit the nail on the head had she posed the question: would the discovery that life can arise by a natural stepwise process, and diversify step-by-step into the various life-forms we find on Earth today, undermine the case for Intelligent Design? And the answer, is Professor William Dembski successfully argued in his essay, Conservation of Information Made Simple, is: No. It merely invites the further question: “where does the information that allows for successful search, whether in biological evolution or in evolutionary computing or in cosmological fine-tuning or wherever, come from in the first place?” For those who read Dembski’s essay, there is only one satisfactory answer to this question: the information required to produce life can only come from an Intelligent Agent.
Professor Dembski and Dr. Robert Marks II have elaborated on this subject in their essay, Life’s Conservation Law: Why Darwinian Evolution Cannot Create Biological Information, where they argue that the discovery that Darwinian evolution was capable of generating Earth’s various life-forms would simply show that Darwinism (contrary to what is commonly assumed) is actually a teleological process:
Darwinian evolution, as it plays out in real life, could potentially look into the future (and thus be teleological) if the fitness it employed were, as Meester puts it, “programmed with insight into the future.” And how do we know that it isn’t? The search algorithms in evolutionary computing give rampant evidence of teleology — from their construction to their execution to the very problems they solve. So too, when we turn to evolutionary biology, we find clear evidence of teleology: despite Dawkins’s denials, biological evolution is locating targets. Indeed, function and viability determine evolution’s targets … and evolution seems to be doing a terrific job finding them. Moreover, given that Darwinian evolution is able to locate such targets, LCI [the Law of Conservation of Information – VJT] underwrites the conclusion that Darwinian evolution is teleologically programmed with active information.
I’d like to conclude by thanking Dr. Liddle for her stimulating essay, and by wishing her a merry Christmas and a happy New Year.