The Definitional Critique of Intelligent Design Theory –Lessons from the Demise of Logical Positivism

The assertion that intelligent design theory ‘isn’t science’ is one of the most popular of the many ‘sound bite’ criticisms of ID repeated with great frequency but little depth in today’s media reports on the origins debate. I call this ‘its not science’ assertion ‘the definitional critique’, in that it assumes the existence of a definition of science that rational people ought to accept and which excludes intelligent design theory. This being so, no rational person could advance ID as a scientific theory. ID theorists routinely advance ID as a scientific theory that should be extended the courtesy of rational consideration. Hence ID theorists like Behe and Dembski are clearly laying claim to a self-contradictory position. They are irrational people with a pseudoscientific ‘theory’ that need not be extended the courtesy of rational consideration – especially not in the course of science education. That, I think, is a fair summary of the definitional critique. It is wrong, and reviewing the history of an influential twentieth century school of philosophy called ‘logical positivism’ can help us to see why.

Once upon a time in Vienna…

There was a time, not so very long ago in the early twentieth century, when thinking about God was an activity nearly banished from academia because many people thought that talk about ‘God’ was literally meaningless. They thought talking about ‘God’ made as much literal sense as the sort of cooing noises adults habitually make to babies: ‘Coochie Coochie Coo!’ In other words, they thought that ‘God-talk’ made no sense at all (beyond its emotive content). God was not the only subject to suffer such banishment. Assertions about right and wrong, beauty and ugliness – indeed, all statements that were metaphysical in nature - were widely considered to be literally nonsense.

The enforcer of this philosophical dress code, the bouncer on the door of academically respectable conversation topics, was the now infamous ‘verification principle’ sponsored by a group of thinkers collectively known as ‘logical positivists’. Philosopher Kelly James Clark explains that logical positivism: ‘began in the early 1920s in an informal discussion group in Austria called the Vienna Circle. The original members, led by physicist Moritz Schlick, included mathematicians, physicists, sociologists and economists but no professional philosophers.’[1] This omission was unfortunate, because: ‘United by their passionate dislike of the metaphysical - the realm beyond the. . . physical world - the group developed a unified philosophy that embraced science and attempted to destroy philosophy.’[2] Attempting to develop a unified philosophy that dispenses with philosophy makes about as much sense as Groucho Marx’s comment that he wouldn’t belong to any club that would have him as a member. Nevertheless, the ideas of the Vienna Circle spread far and wide. The ghost of their attitude towards metaphysics in general (and God in particular) continues to haunt parts of Western academia to this day.

Indeed, the present day sees some critics of intelligent design attempting to exclude discussion of the theory on the grounds that, contrary to the claims of its proponents, ID isn’t scientific. Instead, they hold that ID is at best a philosophical position and at worst an expression of religious faith (and the possession of religious faith on the part of anyone advocating ID is treated as irrefutable proof of the fact that their advocacy is nothing but an expression of that faith – irrespective of their actual theological beliefs - and that the theory itself must have no independent merit worth engaging with – despite growing acceptance by people of many different faiths and none). Moreover, one gets the impression from some of these ‘definitional critics’ that the failure to be scientific is meant to remove ID not only from the schools and universities of America, but from the realm of ideas worth taking seriously. However, the assertion that ID fails to count as science necessarily assumes the existence of a sound demarcation criterion that can divide the scientific from the non-scientific as easily as the logical positivists thought they could divide statements into the meaningful and the meaningless. Both definitional projects fail, and the reasons for their failure overlap.

The Vienna Circle of Exclusion

Despite some disagreement among the members of the Vienna Circle, ‘there was an initial impulse to accept the verification theory of meaning. . .’[3] This theory held that any statement that was not true by definition (e.g. ‘all bachelors are unmarried men’) was only meaningful if it could be empirically verified (at least in principle). To ‘empirically verify’ something means to check it out with the physical senses (sight, hearing, touch, etc.). In other words, the statement ‘This is a book’ is meaningful, because you can verify it by seeing, touching and even smelling this book; but a statement like ‘The sunset is beautiful’ is not meaningful because you can’t verify it’s meaning by seeing or touching or smelling beauty. You can see the sunset, but you can’t see an additional objective reality over and above the sunset called ‘beauty’. Likewise, the statement ‘God exists’ isn’t meaningful, because you can’t verify that either. You can’t literally see, touch or taste God. According to logical positivism, ‘God exists’ is therefore not a meaningful statement that is either true or false, but a use of language on a par with nonsense poetry (like the parts of ‘Jabberwocky’ that Lewis Caroll didn’t define). It may have an emotional resonance, but it has no rational content that can be understood or judged as being either an accurate representation or an inaccurate representation of reality.

Positivism by Ayer Mail

The primary importer of Logical Positivism to Britain was A.J. Ayer (1910-1989). Unlike the members of the Vienna Circle, Alfred Jules Ayer (known to his friends as ‘Freddie’) was a philosopher. Educated in the humanities at Eton College, Ayer studied philosophy at Oxford under Gilbert Ryle before becoming a professor himself, ending up back at Oxford (1947–59) for a time. Ayer served in the British Military during World War II, including a stint in Military Intelligence.

Ayer was immersed in logical positivism during 1932 whilst studying (at Ryle’s recommendation) with Moritz Schlick in Vienna. This visit filled the gap between Ayer’s university finals and taking up his first lectureship. Two years later, Ayer started work on the book that would make his name, a presentation of logical positivism called Language, Truth & Logic, which was published in 1936:

Ayer’s philosophical ideas were largely parasitic on those of the Vienna Circle. However, his clear, vibrant and (arguably) arrogant exposition of them makes Language, Truth and Logic essential reading on the tenets of logical positivism - the book is a classic, and is widely read in philosophy courses around the world.[4]

The term ‘God’ is a metaphysical term. And if ‘God’ is a metaphysical term, then it cannot even be probable that a god exists. For to say that ‘God exists’ is to make a metaphysical utterance which cannot be either true or false. . . If a putative proposition fails to satisfy [the verification] principle, and is not a tautology, then. . . it is metaphysical, and. . . being metaphysical, it is neither true nor false but literally senseless.[5]

As Ayer admitted, positivism entailed that the denial of God’s existence was just as meaningless as the affirmation of his existence, atheism as irrational as theism: ‘If the assertion that there is a god is nonsensical, then the atheist’s assertion that there is no god is equally non-sensical.’[6]

Not only does Ayer’s verification principle exclude all objective talk about God (whether theistic or atheistic) from the realm of meaningful utterances, but all talk of objective goodness and beauty as well. According to Ayer:

Such aesthetic words as ‘beautiful’ and ‘hideous’ are employed, not to make statements of fact, but simply to express certain feelings and evoke a certain response. It follows, as in ethics, that there is no sense in attributing objective validity to aesthetic judgements, and no possibility of arguing about questions of value in aesthetics... there is nothing in aesthetics, any more than there is in ethics, to justify the view that it embodies a unique type of knowledge. It should now be clear that the only information which we can legitimately derive from the study of our aesthetic and moral experiences is information about our own mental and physical make-up.[7]

Ayer’s contemporary, Catholic philosopher F.C. Copleston, observed that: ‘Ayer’s writings [have] exercised a widespread influence, particularly perhaps on university students, for whom it possessed the charm of novelty and an atmosphere of daring.’[8] Play-write William Cash calls Ayer: ‘arguably the most influential 20th century rationalist after Bertrand Russell.’[9] Ayer’s declaration that God-talk was nonsense influenced an entire generation of scholars, despite the fact that his book originally only sold ‘just over 1,000 copies (64 years later, the book still sells 2,000 a year in Britain: a 1945 reprint in the United States has sold 300,000).’[10] As Hilary Spurling observes:

It was one of those books that galvanize a whole generation. Ambitious undergraduates commonly read it at a sitting. Their elders were appalled. When students tried to discuss the book at an Oxford seminar, the Master of Balliol flung it through the window. Ayer was denounced by a housemaster at Winchester School as the wickedest man in Oxford. Asked what came next, the young iconoclast said cheerfully: ‘There’s no next. Philosophy has come to an end. Finished.’[11]

A Negative Assessment of Logical Positivism

In 1943 E.L. Mascall observed that: ‘the logical positivists’ position seems to be crumbling from within...’[12] Just two decades after Language, Truth and Logic was published, F.C. Copleston could write: ‘there are few British philosophers who willingly accept the title of “positivists” or who make open profession of applying the principle of verifiability as a criterion of meaning... [positivism] is no longer fashionable.’[13] A number of factors explain the demise of positivism.

Verifying God

As philosopher John Hick pointed out, when made precise enough, the statement that ‘God exists’ is empirically verifiable (at least in principle, which is all that the principle of verification requires). Hick argued that:

A set of expectations based upon faith in the historic Jesus as the incarnation of God, and in his teaching as being divinely authoritative, could be so fully confirmed in post-mortem experience as to leave no grounds for rational doubt as to the validity of that faith.[14]

If you were to die and then find yourself in a clearly Christian afterlife - that is, you are given a resurrected body and a life in a community of Christians that revolves around the resurrected and ascended Jesus Christ - one could surely count this experience as an indirect empirical verification of God’s existence. Just as empirical measurement of the background radiation of the universe provides indirect empirical verification of the big bang in cosmology (to see one isn’t to see the other, but to see the one is to see something from which the other can be inferred)[15], so experiencing the sort of afterlife promised in the New Testament would likewise provide indirect empirical verification of God’s existence. This being so, the claim that God exists is open to verification in principle, and therefore counts as being a meaningful claim according to the principle verification. As Hick concluded: ‘the existence or non-existence of the God of the New Testament is a matter of fact, and claims as such eventual experiential verification.’[16]

Unless positivism is framed broadly enough to allow this sort of indirect verification, many explanatory entities within science would count as nonsense, because they are verified indirectly (being inferred from observation of their hypothesised effects). For example, scientific theories about so-called ‘dark matter’ would count as meaningless under the verification principle if it excluded indirect verification.[17] The verification principle cannot be used to wall off scientific claims about the universe from religious claims about its creator, because however it is formulated, it either lets too much or too little into the category of ‘claims that are meaningful’. Hence, as philosopher Llyod Eby observes: ‘All attempts to solve this problem of having a version of the verification principle… that admits all scientific statements but excludes all metaphysical statements have met with failure.’[18]

It might be argued that the God hypothesis is not only verifiable in principle (as Hick argued) but also in practice, since several of the arguments for God can be framed using the scientific method of indirect verification (e.g. arguments from miracles, personal transformation, etc). Such an approach underlies the entire natural theology project of noted Oxford philosopher of religion Richard Swinburne.[19] As Basil Mitchell comments:

the Logical Positivist movement started as an attempt to make a clear demarcation between science and common sense on the one hand, and metaphysics and theology on the other. But work in the philosophy of science convinced people that what the Logical Postitivists had said about science was not true, and, by the time the philosophers of science had developed and amplified their accounts of how rationality works in science, people discovered that similar accounts applied equally well to the areas which they had previously sought to exclude, namely theology and metaphysics.[20]

Ironically for those materialists who embraced logical positivism, ‘materialism would have to be rejected as nonsense by a strict interpretation of logical positivism’.[21] The claim that matter is objectively real is, after all, neither true by definition nor something that can be verified by sense data (since it is the nature of what the senses perceive that is in question). Positivism makes not only materialism, but also a realist account of science, impossible. As F.C. Copleston argued in his famous BBC debate on positivism with Ayer:

if the meaning of an existential proposition consists, according to the principle, in its verifiability, it is impossible, I think, to escape an infinite regress, since the verification will still itself need verification, and so on indefinitely. If this is so, then all [existential] propositions, including scientific ones, are meaningless.[22]

Verifictionism is either self-contradictory or arbitrary

Finally, as R. Douglas Geivett explains, chief among the woes of Logical Postivism was the fact that the verification principle ‘was neither empirically verifiable nor tautological.’[23] That is, the verification principle was itself a metaphysical claim, a claim that therefore ruled itself to be meaningless: ‘it failed its own requirement for factual meaningfulness’, notes William P. Alston, ‘and thus was self-refuting.’[24] Roger Scruton observes: ‘Logical positivism no longer has a following, and it is easy to see why. The verification principle cannot be verified: it therefore condemns itself as meaningless.’[25] As Copleston argued in his debate with Ayer:

the principle of verification… is either a proposition or no proposition. If it is, it must be, on your premises, either a tautology or an empirical hypothesis. If the former, no conclusion follows as to metaphysics. If the latter, the principle itself would require verification. But the principle of verification cannot itself be verified. If, however, the principle is not a proposition, it must, on your premises, be meaningless.[26]

Ayer tried to get around this problem by admitting that the verification principle wasn’t a meaningful proposition but saying that it was a rule for using language. But why pay attention to such an arbitrary rule? As Ayer himself asked: ‘why should anyone follow the prescription if its implications were not to his taste?’ [27] Philosopher Keith Ward reports the following conversation between Ayer and a student:

A student once asked [Ayer] if you could make any true general statement about meaningful statements. ‘Yes,’ he replied. ‘You can say that all meaningful statements must be verifiable in principle.’ ‘I see what you mean,’ said the student. ‘But how can I verify that?’ ‘I am glad you asked that,’ said the philosopher. ‘You cannot verify it. But it is not really a meaningful statement; it is just a rule for using language.’ ‘Whose rule?’ ‘Well, it’s my rule, really. But it is a very useful one. If you use it, you will find you agree with me completely. I think that would be very useful.’[28]

If we adopt the rule, then of course we will agree with Ayer, and of course Ayer will find that useful! But he can’t provide us with a reason for adopting his rule (certainly not one that doesn’t implicitly contradict the rule he wants us to adopt). Instead, he recommends it on the basis of its usefulness. Usefulness for what? For insulating a worldview that excludes everything metaphysical, especially religion (as the positivist’s failed attempts to produce a version of the principle able to draw a line of demarcation between science on the one hand religion on the other hand, shows). Indeed, at heart I suspect that the motivation behind logical positivism is the desire to exclude God by excluding talk about God. Logical positivism was quite simply a form of atheistic censorship. However, the younger generation of philosophers, like Ward, who opposed this baseless peer-pressure were well within their rights to point out that the Emperor of positivism had no clothes, but brazenly walked the halls of academia with nothing but a smile of fashionable popularity to disguise his self-contradicting ways.

The Verdict on Verificationism

James Kelly Clark describes the verification principle as a piece of ‘unjustifiable philosophical imperialism that, in the end, could not survive critical scrutiny.’[29] William Lane Craig comments: ‘Fifty years ago philosophers widely regarded talk about God as literally meaningless... but today no informed philosopher could take such a viewpoint.’[30] Ronald H. Nash concludes that logical positivism ‘is dead and quite properly so.’[31] Ayer himself mused: ‘I just stated [the verification rule] dogmatically and an extraordinary number of people seemed to be convinced by my assertion.’[32] By 1973 Ayer admitted: ‘the verification principle is defective...’[33] Talking about positivism during an interview in 1978, Ayer conceded: ‘Nearly all of it was false.’[34] Philosopher Roy Abraham Varghese reports Ayer as affirming: ‘Logical Positivism died a long time ago. I don’t think much of Language, Truth and Logic is true. I think it is full of mistakes.’[35]

The Resurrection of God-Talk

On 8 April 1966, Time Magazine ran a cover story about the then current ‘death-of-God’ movement in American theology entitled ‘Is God Dead?’ William Lane Craig explains that: ‘According to the movement’s protagonists, traditional theism was no longer tenable and had to be once and for all abandoned. Ironically, however, at the same time that theologians were writing God’s obituary, a new generation of young philosophers was rediscovered His vitality.’[36] Only a few years later, Time carried a cover story asking ‘Is God coming back to life?’ Interest in the philosophy of religion continued to grow to the point where, in 1980, Time found itself running a story about ‘Modernizing the case for God’, describing the contemporary movement among philosophers putting new life into the arguments for God’s existence:

In a quiet revolution in thought and argument that hardly anybody could have foreseen only two decades ago, God is making a comeback. Most intriguingly, this is happening not amongst theologians or ordinary believers, but in the crisp intellectual circles of academic philosophers, where the consensus had long banished the Almighty from fruitful discourse.[37]

The reference to banishing the Almighty from fruitful discourse is a reference to logical positivism. Hence it is no surprise to find Tyler Burge, Professor of philosophy at UCLA, writing that the central event in philosophy during the last half-century was ‘the downfall of positivism and the re-opening of discussion of virtually all the traditional problems of philosophy.’[38] The death of positivism meant that questions of metaphysics, including the existence of God, were once again live issues in the world of academia.

Lessons for Definitional Critics of Intelligent Design

When critics of intelligent design theory attack it as not being scientific, they necessarily presuppose the existence of a sound demarcation criteria able to distinguish between ‘science’ and ‘non-science’, just as positivists assumed the existence of a sound demarcation criteria able to distinguish between the ‘sense’ of ‘science’ and the ‘non-sense’ of metaphysics. (Of course, the failure of logical positivism means that even if ID is not science, it might nevertheless be a true philosophical claim.) The failure of logical positivism should, I think, give pause for thought to the definitional critics of ID. Indeed, just as the verification principle ruled either too little or too much ‘in’ to the positivists’ favoured category of ‘science’, so the demarcation criteria of ID’s critics does the same.

On the one hand, critics sometimes define ID as requiring belief in a supernatural explanation. They then attack ID on the basis that the rule of ‘methodological naturalism’ (i.e. mentioning anything supernatural isn’t scientific) is a sound demarcation criterion between ‘science’ and ‘non-science’. However, not only has it been cogently argued by philosophers of science that methodological naturalism is not a sound demarcation criterion,[39] and that reference to the supernatural is not necessarily unscientific (the thought that it was would have been news to Newton),[40] but ID theorists themselves define their theory as not requiring supernatural explanations! Michael Behe writes:

my argument is limited to design itself; I strongly emphasize that it is not an argument for the existence of a benevolent God, as Paley’s was. I hasten to add that I myself do believe in a benevolent God, and I recognize that philosophy and theology may be able to extend the argument. But a scientific argument for design in biology does not reach that far. Thus while I argue for design, the question of the identity of the designer is left open... as regards the identity of the designer, modern ID theory happily echoes Isaac Newton’s phrase, hypothesis non fingo.[41]

Consider an analogy: many people believe that the best philosophical explanation of Big Bang cosmology is theistic (indeed, there have been atheists who opposed Big Bang cosmology because they believed this),[42] but this fact does not mean that Big Bang cosmology isn’t a scientific theory, or that it cannot be accepted by atheists! Likewise ID. As I have argued out elsewhere,[43] abstracted from a conclusion to the philosophical question of the ontological nature of intelligence, ID is compatible with naturalism (as any Raelian will tell you[44]). All ID infers is intelligent explanations. As Geoscientist Marcus R. Ross correctly explained in a presentation before the Geological Society of America, ‘ID is classified as a philosophically minimalistic position, asserting that real design exists in nature and is empirically detectable by the methods of science.’[45] Therefore, unless naturalists are prepared to admit that intelligent explanations are necessarily supernatural (wave goodbye to naturalism), naturalists cannot accuse ID of requiring supernatural explanations without contradicting themselves (after all, one would need to appeal to intelligence to explain their published critique). In this sense, then, ID is as ‘methodologically naturalistic’ as the next scientist. Of course, an ID theorist might believe on philosophical grounds that intelligent explanations are necessarily supernatural explanations – but such a belief is no more inherent within ID as a scientific theory than is the belief that the designer must be the God of mono-theistic religious belief.

On the other hand, if you decide to define ‘science’ so that it excludes explaining anything with reference to intelligence, then of course ID isn’t ‘science’ in that sense of the term. But then, neither is forensic science, archaeology, psychology, cryptography or SETI (the search for extra-terrestrial intelligence)! Just as the logical positivist’s failed to define their verification principle in such a way as to exclude ‘religious’ claims whilst including ‘scientific’ claims, so the definitional critics of ID fail to define ‘science’ in such a way as to exclude ID whilst including claims that even they admit are scientific. Either both are in, or numerous things that even ID’s critics accept are scientific are out. As ID critic Bradley Monton argues, ‘ID should not be dismissed on the grounds that it is unscientific.’[46]

What matters in the final analysis is a) the existence of reliable design detection criteria (something already accepted by various sciences and even by many critics of ID) and b) the existence of evidence that warrants a design inference according to thee criteria.[47] If adequate criteria and empirical evidence both exist, then the conclusion of intelligent design follows. And although an acceptance of ID does not automatically equate with an acceptance of supernaturalism, let alone theism, if ID should lead one to ponder whether God mightn’t be the best candidate for the source of design, that possibility can’t be dismissed as nonsense simply because it is metaphysical.