Evolutionary contingency and the purpose of the cosmos
Author: Ernan McMullin. University of Notre Dame (USA)
Published in Scripta Theologica, 30 (1998), pp. 227-251.
Does the contingency of the evolutionary account of origins, especially of man, make it more difficult to see the universe as the work of a Creator? Does it effectively leave out finality at the cosmic level and us in a world stripped of all religious meaning? Some would agree to both questions. It has always been clear that chance plays an important role in Darwin's theory. But somehow it seems easier to conceive of evolution as the divine way of realising divine ends when evolution itself is understood as a process whose general form would be anticipated, and therefore could be trusted to carry out the divine plan. The emphasis on the contingency of evolutionary outcomes by authors such as Monod and Gould could easily suggest that ours is a universe in whose processes finality could not be imposed, even by a Creator.
In this essay, I would first like to highlight two very different conceptions of evolution. According to the first, evolution is, roughly speaking, predictable under the right conditions; natural selection works more or less regularly, leading to increasing complexity. According to the second, evolution is not predictable at all; contingency limits the possibilities of selection so strongly that the results simply cannot be anticipated, even in the most general way. One way in which the contingency of the evolutionary account of man's origin can be answered from the theistic point of view would be the assumption that God "intervened", in one sense or another of this inappropriate term, to bring about the emergence of mankind. But there is another alternative. In the final section of this essay, I outline the traditional doctrine of the eternity of God in order to decide whether, on this view, the contingency of evolutionary processes must necessarily have the negative significance often attributed to it with respect to the finality of the cosmos. If the Creator is understood as outside the limits imposed by temporality, would radical contingency still offer evolutionary outcomes impenetrable to the Creator's purposes?
1. Predicting developments
Some may not be familiar with the "extraterrestrial civilisation equation" which was first formulated by radio astronomer Frank Drake in the 1960s. Drake and some of his colleagues were convinced that the powerful new technology of the radio telescope should be used in a systematic effort to discover whether there were radio messages sent in our direction by extraterrestrial civilisations advanced enough to be able to broadcast such signals. To justify spending precious time on these expensive instruments and for such a search, it was crucial to make an estimate of how likely it was that such a civilisation existed and, if so, at what issue. How likely was it that a civilisation existed at, say, twenty light-years from us? Even with one so close, the forty-year interval between message and reply would result in a very slow dialogue.
At a lecture on extraterrestrial intelligence sponsored by the National Academy of Sciences in 1961, Drake proposed the following equation:
N =R Fp Ne Fl Fi Fc L
N is the issue of civilisations in our galaxy with sufficient capacity and interest for interstellar speech . R is the average annual level of training of stars over the lifetime of the galaxy; Fp is the fraction of stars with planetary systems; Ne is the average issue of planets in such systems with environments favourable to the origin of life; Fl is the fraction of such planets where life develops; Fi is the fraction of these planets where intelligent life with manipulative capability arises during the lifetime of the local sun; Fc is the fraction of these planets that produce a technically advanced civilisation; and L is the duration average of such a civilisation * (1).
This may not seem to get us very far in calculating the value of N, given that there are seven unknown quantities on the other side of the equation. But Drake, and with him Carl Sagan, were not overwhelmed by this challenge and proceeded to give an estimated issue to each magnitude. Sagan's figures are: 10, 1, 1, 1, 1, 10-1, 10-1, 10-1, for the first six. L caused him more problems: could a technological civilisation self-destruct so that its average lifetime could not exceed a hundred years, or would it control its violent impulses and establish a stable mode of existence that could last as long as the planet did (>108 years)? The first value of L would imply that N would only be of the order of 10; the second, that N would be >107. As a compromise measure, Sagan set 106 as a reasonable estimate of the issue of technically advanced civilisations in our galaxy. And so this figure achieved a certain status in the literature on extraterrestrial intelligence * (2).
There is obviously much to be said about this rather sloppy calculation* (3). But what interests me here is Sagan's idea of biological evolution as a process which, given the right conditions, will necessarily occur and in the course of time will necessarily give rise to intelligence. Without such an assumption, the value of N could not be estimated, even in the most cursory way. This way of understanding the operation of natural selection has of course been very common. Textbook treatments of Darwin's theory often present it as a simple consequence of the action of natural selection: heritable variations that favour differential survival of offspring will tend to spread the population. There may be additional complications due to geographical isolation, environmental change, etc., but the impression is of a gradual but steady direction towards increasing complexity. The organic Structures become more complex as new organs are developed and old ones find new uses. Intelligence itself, with its enormous advantage for survival and propagation, may then seem an almost inevitable development , if the time scale is generous enough.
This view of the "upward and forward" action of evolution finds some support in the text of The Origin of Species itself:
Natural selection acts, as we have seen, excusively through the presentation and accumulation of variations which are beneficial under the organic and inorganic conditions of life to which each creature is exposed at each successive period. The ultimate result will be that each creature will tend to become more and more improved in relation to its living conditions. This improvement, I believe, will inevitably lead inevitably to the gradual advancement of the organisation of the largest issue of living beings in the whole world * (4).
But it was among philosophers that this perspective perhaps found the warmest welcome, at least among those who regarded evolution as the core topic for their cosmology and their Philosophy in general. Herbert Spencer formulated a "law" of evolution which, he believed, would govern not only living things but the physical world in general. Organic structure tends to become more differentiated over time, with the constant appearance of new forms of integration. Following Lamarck, he argued that the employment or not of an organ could lead to heritable changes in function. Later philosophers, such as Lloyd Morgan, Samuel Alexander and Henri Bergson, proposed theories of evolution that deviated even more than Spencer from Darwin's rule , agreeing with agreement that evolution is a relatively constant and progressive process.
It is noteworthy that those philosophers who have described evolution in strongly progressive terms tend (Spencer would be an obvious exception) to regard evolution as God's mode of action in the world. This conjunction finds its most striking expression, perhaps, in the work of Pierre Teilhard de Chardin. He sought an explanation for the constant "complexification" he found in the fossilised account of life in a "psychic" or "radial" energy operating directionally, as opposed to the "tangential" energies dealt with in physics and Chemistry. Although he concedes a Degree of "groping" along the way, evolution is for him "a great orthogenesis of all that lives towards a higher Degree of immanent spontaneity", "a spiral that grows upwards as it turns. From one geological layer to another, something is transmitted: it grows slowly, but steadily and in a constant direction" * (5). Of course, so constant has been the upward curve in his theory that he felt compelled to extend it to the remote future of an Omega point where consciousness would be fully realised, a Final Cause where an explanation will be found for the whole course of evolution, which is inexorably heading in that direction.
Few evolutionary philosophers were as confidently orthogenetic in their understanding of the process of evolution. But philosophers, like physicists and geologists who compute the probability of intelligent life in the universe, on the whole have tended to see, more than biologists, the operation of evolution in terms of a law, a force analogous to Newton's gravity that endlessly shifts the gene pool to create more and more complex organisms. From this interpretation, evolutionary theory becomes a resource for prediction and no longer just an explanation of the radiation of living forms in the past.
2. The contingency of evolution
Those who shaped the "new synthesis" in evolutionary biology during the past half-century were never comfortable with the predictive uses of evolutionary theory by exobiologists and others, and flatly opposed orthogenesis in any shape or form. Ernst Mayr and Theodosius Dobzhansky were among those who expressed scepticism about this understanding of evolutionary modes of explanation. Perhaps the most significant critic was George Gaylord Simpson, who in his This View of Life developed an extended polemic against the presuppositions underlying the predictivist attitude. He stressed in particular the fundamental differences between the non-historical natural sciences, such as physics and Chemistry, and the historical sciences: geology, palaeontology and evolutionary biology. The latter deals with unique events for which the notion of law applicable in physics simply does not work. The complexity of the interaction between environment and genetic change is so great that any attempt to derive "general lines" or "trends" is doomed to failure. "There is a direction, but it varies, and there are also chance effects" * (6).
In Chance and Necessity (1971), Jacques Monod celebrated the decisive role of chance in evolution. Since DNA mutations
"The fact that the genetic text is the only possible source of changes in the genetic text, and that it is the only repository of the organism's hereditary Structures , necessarily means that chance alone is at the root of all innovation, of all creation in the biosphere. Pure chance, absolutely free but blind, at the very root of the fabulous edifice of evolution: this central concept of modern biology is no longer one among other possible or conceivable hypotheses; today it is the only conceivable hypothesis" * (7).
For him, mutations are chance events in two senses. First, they represent the convergence of previously unrelated causal chains; second, they are quantum events and therefore essentially unpredictable. The course of evolution is thus itself unpredictable in detail. But despite the far-reaching consequences Monod draws from this primacy of chance in the history of evolution (losing our "necessary place in the outline of nature" condemns us "to an icy universe of solitude" * (8)), he is still willing to concede that evolution follows "a generally progressive course", that its direction is "upward", that the subjection to certain types of behaviour in particular groups "orients the species irevocably in the direction of a continuous refinement of the Structures and executions which this behaviour requires as a support" * (9). Thus, after all, the operation of natural selection seems to restore a certain Degree of directionality, and even progress, in the course of evolution.
Stephen Jay Gould takes a much stronger line in considering the contingency of evolutionary change. He does not accept any "upward trends" or "trends", or a more modest subject predictability. And it does not emphasise the randomness of either the mutations that provide the material for natural selection or the drift Genetics in the original populations. Rather, it emphasises the general lack of relationship between the multiple lines of causation affecting singular historical events, such as changes in the composition Genetics of a population.
In his popular essays, he returns again and again to the flexibility of the evolutionary process, which makes it something more than a simple selectionist version would lead one to believe. In the essay that gives degree scroll to Eight Little Piggies, he argues that the pentadactyl limb that we share with so many other mammalian species "just happens to be there". This should not necessarily be taken as evidence that five has been inherently favoured in adaptation, over other possible numbers of toes; the earliest tetrapods, in fact, had seven or eight toes. Rather, issue may derive from
"The complex, unrepeatable and unpredictable events of history. We are trained to think that the quantification, experimentation and replication models of 'hard science' are per se superior and exclusively canonical, so that any other group of techniques pale in comparison. But historical science proceeds by reconstructing a set of contingent events, retrospectively explaining what could not be predicted beforehand.... Contingency is rich and fascinating; it embodies an exquisite tension between the power of individuals to change history and the intelligible limits imposed by the laws of nature. The details of the lives of individuals and species are not mere ornaments, with no capacity to shape large-scale courses of events, but particularities that can completely, profoundly and definitively alter the future" * (10).
The nature of history and historical science is the topic around which he organised in Wonderful Life his entertaining study of the successive and conflicting interpretations of the Cambrian fauna found at Burgess Shale. He has long been critical of the gradualism of the traditional Darwinian version of the operation of natural selection, calling instead for "a punctuated equilibrium" in which long periods of stability, in which species remain more or less identical, alternate with moments of relatively sudden speciation*(11). In his ambitious work, he reconstructs the extraordinary original flowering of the most important "phyla" of almost all modern animal groups within a geologically and biologically brief interval of a few million years, during the Cambrian period, which began about 570 million years ago. What fascinates Gould most about the "Cambrian explosion", as it has been called, is not only the fact that the "phyla" appeared in such a short time span, nor that no more have appeared since, but that a vast majority of the "basic plans" of arthropods found at Burgess Shale lack modern representatives. In other words, of the approximately twenty-five distinct anatomical designs found, any one of which could, according to Gould, have served as the ancestor for a distinct phylum, only four survived the Cambrian period and gave rise to modern animal phyla. It is this decimation of phylum candidates, this "lottery" as he calls it, that Gould sees as testimony to the effects of historical contingency. The conventional answer, of course, would be that the four surviving ancestors were somehow better adapted to changing environmental conditions. Gould does not find this plausible. But even if this had been the case, under a different environmental scenario the list of survivors, he says, would have been quite different. And everything that has followed would then have taken a different direction.
Gould's emphasis on extinctions, particularly the great extinctions of life that signalled the end of the Permian period, when up to 96% of marine species died out, and of the Cretaceous, when the dinosaurs disappeared, is somewhat reminiscent of the catastrophism that inflamed the geological discussion two centuries ago. His view is that in such episodes the natural selection of the usual subject would cease to operate; it would largely be a matter of chance which of all existing species would survive to propagate in an unpopulated world. Moreover, the causes of such mass extinctions are a matter of chance, relative to the previous history of the affected populations. Thus, he concludes:
"Since dinosaurs did not evolve much larger brains, and since this possibility may lie outside the capabilities of the reptilian constitution, we must assume that consciousness would not have occurred on our planet if a cosmic catastrophe had not befallen the dinosaurs"* (12).
The strength of Gould's example lies in his insistence on the importance of network necessary conditions in any explanation of a complex historical event, that is, conditions in the absence of which result would have been different, perhaps completely different. A specific source of contingency to which he often returns is the constraint imposed on the possible adaptive lines of development in a particular population by the accessibility, in some corner of that population and for various reasons, of the appropriate anatomical framework for that development. Thus, a mysterious group (the coelacanth/lungfish) that would belong to the broad domain of fish species of the Devonian period turned out to have the subject skeleton that would allow the development of limbs, making locomotion on land possible. Had these species not existed, as might have been the case, Gould stresses, amphibians could not have invaded the land, which until then might have been inhabited exclusively by insects*(13).
Few have taken the topic of contingency as far as Gould; others have found his emphasis exaggerated*(14). He is, of course, right about the presence of contingency in the path of evolution actually followed so far. But the question remains: how does one know what would have happened if life had taken another path along the way? Or more precisely: how can one say that life on land would not have developed if the lungfish had not been around at the right time, or that consciousness would not have developed if an asteroid had not collided or climate change had not covered Africa with forest mass three or four million years ago? Moreover, the overwhelming evidence of the parallel evolution of organs such as the eye or of physiologically very similar species should give you pause for thought. It seems as if contingency has, in many instances, been overcome by strong selective advantage.
There seems then to be a considerable risk in adopting either of the extremes set out, the resource to laws or trends that would allow the claim that life on earth or the emergence of intelligence would have arrived anyway, and the emphasis on a radical contingency that allows Gould to conclude that homo sapiens is "a twig on an unlikely branch of a contingent limb of a fortunate tree". "Start the tape over a million times from a Burgess-like beginning", he stresses, "and I doubt if anything like homo sapiens could ever come out of evolution again"* (15). How can we be so sure of either the inevitability or the improbability of the emergence of intelligence?
Most evolutionary biologists and philosophers of biology seem to take a middle position between these two extremes, but this still allows for much ambiguity. Dobzhansky, for example, objects to what he sees as Monod's overemphasis on chance. On the contrary, he points out: "looking at the evolution of the living world as a whole, from the hypothetical original self-reproducing substance to plants, animals and man, one cannot help but recognise that progress, or advancement, or emergence, or ennoblement, has taken place"* (16). Although chance predominates in mutation and recombination, he goes on to say, natural selection serves to balance it as an "anti-chance" factor. Thus, although the course of evolution cannot be predicted, "it does not follow that the human species arose by a lucky throw of celestial dice or evolution"* (17). In a recent review of topic, Elliott Sober is more cautious. He is sceptical about the suggestion that the process of evolution has shown progress or even any direction in the past. Although there may be directional trends along specific lines, all that the theory of natural selection allows us to conclude is that such trends are possible. It does not, however, allow us to anticipate them; the various sources of contingency preclude this possibility.
What can we conclude from this rapid summary? Macroevolution is an irregular process, which admits breaks, reversals, large-scale extinctions. We can, at least in principle, explain its course a posteriori, but we cannot anticipate it. The last billion years have seen an enormous increase in the variety and issue of species. internship At the same time there has been a growth in the complexity of organisms that (in the view of some) can be conceived as a form of progress; however, it has proved difficult to find a consensus definition of what "complexity" and "progress" should mean in this context*(18). Nevertheless, as palaeontological and geological data are increasingly scrutinised and genetic mechanisms are better understood, the fragile nature of the causal chain leading to the emergence of humans becomes more evident.
What are the theological implications of all this, if any? Faith in a Creator has always gone hand in hand with the conviction that the human race plays a special role in the creation story: made in the image of God, we are the only creatures so far known capable of denying or freely offering their love to the Creator. Jews, Christians and Muslims would agree in supposing that as far as we can speak of God's plans at all, we can assume that humans have an important role in at least one corner of them. It seems to follow, then, that the emergence of the human species would not have been left to chance. If it was part of the Creator's purpose that men made their entrance on planet Earth after a preparation of fifteen billion years, can the history of this long prelude be driven by contingency, as it seems? Conversely, if one accepts the thesis of contingency, even if not in as radical a form as Gould proposes, does this not cast doubt on the belief that the Creator intended the cosmos to bring forth human beings? And if it does, would it not call into question the whole notion of an omnipotent God whose purposes make sense of an otherwise absurd universe?
The sincere anthropocentrism of the research line that these questions open up runs, of course, counter to the instinct of scientists who sometimes appeal to a "Copernican principle" to justify their refusal to guarantee any form of privilege for human beings. But Western theology is anthropocentric by nature; it treats human destiny as a central issue. When theologians skip over the eons of evolutionary time that were necessary for the production of human beings and focus on the relationship between those beings and God, the form their research takes will necessarily seem alien to scientists who look at human beings as one knot, albeit a particularly complex knot, in a vast network of types of life. But if scientists should be more careful not to rush to judgment when their theological colleagues focus on human destiny, theologians need to take seriously what the sciences have to say about how human beings first came into existence. All this is an apology for a essay that clearly transgresses the divides between the two disciplines.
3. Evolution and teleology
Questions about whether human evolution can be seen as the work of a divine purpose immediately recall a more conventional but no less lively discussion about the extent to which evolutionary explanation can be considered teleological. The common view is that Darwin expelled teleological explanation from the field of evolution; a view, of course, that Darwin himself and many of his antagonists shared*(19). But we find some recent authors who reason, on the contrary, that evolutionary theory is formally teleological in nature*(20). It is not necessary for my purpose to explore this ambiguity in detail here*(21). Suffice it to say that from its very beginnings in the work of Plato and Aristotle, the notion of teleology could be considered in two very different directions.
On the one hand, a telos or end would directly imply a mind. A teleological explanation would in this case imply a resource to the activity of the mind, to intentionality. One particular form played an important role in the history of natural science, which is why it was called "the argument from design". In the Timaeus, Plato appealed to an Artisan of the cosmos, the Demiurge, to explain the numerous traces of order observable in the sensible world. An intelligible order testifies to the activity of a Nous (Mind, Reason). The explanation of this order points not to a specific plan but to the necessity of Someone who proposes a plan. And, again, the advocates of natural theology in the 17th century started from the clear evidence of adaptation of means to ends in the anatomical Structures and instinctive behaviours of the animal world. Since such adaptation would require a deep understanding of the needs of each subject animal, a cosmic Designer of animal natures would be the manager. "design" here means a form of order that directly testifies to the operation in nature of a conforming intelligence. A theological explanation in this sense can therefore serve not only to explain a set of phenomena but, more significantly, to demonstrate the existence of a being capable of carrying out the process of design of the cosmos.
This is the subject argument that Darwin undermined. His theory of natural selection set out to explain exactly those modes of adaptation that had previously been employee seen as evidence for an original Designer. When Darwin and his later followers claimed to have eliminated teleology from the science of living things, this is what was uppermost in their minds. Not everyone was convinced, of course, and among those who accepted the historical fact of evolution, some, like Bergson, proposed another subject teleological explanation of how it took place. Instead of a transcendent Designer, they proposed a quasi-intelligent energy or impetus operating throughout the history of life, giving it its direction and meaning. They argued that natural selection alone, relying as it does on chance because of the material with which it operates, could in no way obtain the progressively intricate and admirably balanced Structures that the history of the living world presents.
When advocates of the new synthesis, such as Simpson and Mayr, reject teleology, it is this form of intentional explanation that they have in mind. One can see why they react so vehemently against it, since it calls into question the adequacy of Darwinian models of explanation. Daniel Dennett is only the latest in a series of acerbic critics of the most prominent recent representative of this form of teleology, Teilhard de Chardin:
"Theesteem with which Teilhard's book is still received among non-scientists, the respectful tone in which his ideas are alluded to, testifies to the depth of abhorrence for Darwin's dangerous idea, an abhorrence so great that it excuses any lack of logic and tolerates any opacity in what is supposed to be an argument, if at bottom it promises to relieve us from the oppression of Darwinism"* (22).
The feeling of revulsion is obviously not only in one of the parts of discussion!
It seems fair to say that the teleological explanation of this basically idealistic subject is almost universally dismissed among evolutionary scientists. The possibility that a "radial" energy or vital élan of some subject is manager of at least part of the goal-oriented aspects of macroevolution cannot, of course, be definitively excluded. And the obvious bias of the neo-Darwinist programs of study can easily be used to lay the foundations of this "heresy", as Dennett calls it. But as time goes on, the steady extension of neo-Darwinian forms of explanation to the mountains of data that palaeontologists and biologists are amassing makes the chances of this "heretical" attitude prevailing seem even more remote. Nevertheless, its appeal, especially to non-scientists, is undoubted. After all, it still seems counterintuitive that subtleties of anatomical structure and function in the living world could be due entirely to natural selection operating on deviant mutations, no matter how long the time span. That evolutionary scientists do not see it this way is undoubtedly due in part to their conviction that the teleological alternative is even less credible because of the challenge it offers to the common methods of empirical science.
There is, however, a different sense (or set of senses) of teleology, going back more to Aristotle than to Plato, which allows many to claim that evolutionary theory is still basically "teleological" in form. The resource here is not to a mind or a conscious purpose but to function, to the role played by the part in the whole, for example. Aristotle's De Partibus Animalium is replete with examples of what he calls "that for whose purpose": the liver is for mixing; the adipose tissue around the kidneys is for producing heat, and so on. This subject of purpose is taken by Aristotle as a defining characteristic of living things. A functional-teleological explanation, as we might call it, consists of two parts. First, the function of the part (e.g. digestion of food) is deduced, and then the meaning of this function to serve the needs of the organism is deduced. The liver is thus necessary for the well-being of the organism; Aristotle has much to say about the subject of hypothetical necessity that is implied in explanations of this class* (23).
A similar form of teleological explanation deals with the processes that constitute the natural world. Aristotle explains these processes by specifying the term to which they regularly tend, this term being taken as a completion of the nature involved, in a certain sense. The explanation here appeals to telos in its most literal sense. And for Aristotle it extends to all physical beings, living or not. The end of the falling motion of heavy bodies, for example, is to return to the natural place of those bodies. Every habitual mode of nature's behaviour maintains that place of nature in a cosmic order; it is a good both for individual nature and for that higher order. Aristotle sees ontogeny as the paradigm of these end-directed processes, in the constant development from embryo to adult found in all living things. The maturity of the adult form is evidently the goal of the process from its beginning. This tendency of the natural process towards an end that is beneficial to the individual or the species is not a conscious effort. It is found in elements such as the earth as well as in the higher animals. There is no suggestion, in Aristotle's study, of the intentionality which Plato postulated as an explanation of the traces of intelligible form in the sensible order. The sharp distinctions Aristotle offers between living and non-living, and between rational and non-rational, make it quite clear that the subject of immanent final cause which he postulates as an explanation of natural process is not to be interpreted as intentional, although some critics have misunderstood him in this respect from the seventeenth century onwards*(24).
resource he function and resource altelos of the natural process are not the same, but they are closely related and neither necessarily involves the causal action of a mind, life-force or the like. It is to these non-intentional forms of teleology that philosophers who regard evolutionary theory as formally teleological refer. Wimsatt, for example, argues that a trait is 'selected', in the Darwinian sense, if it serves a function of the population concerned. Likewise, it could be argued that the operation of natural selection is "for the benefit of nature" and, consequently, could be said to have a telos in the Aristotelian sense*(25). At this point, the discussion becomes rather complicated and one has to consider all subject of nuances*(26).
For my present purposes, these discussions are not relevant. Even if one grants that evolutionary theory is teleological in this second sense, it is not implied that there is anything revealing of a purpose in the processes under consideration. So in our attempt to answer the theological questions raised by the contingency of the evolutionary process it is of little relevance financial aid. Those questions, moreover, concern macroevolution; the teleology to which Wimsatt and others give attention concerns, as far as I can see, only microevolution. We must therefore take another direction.
4. Purpose and contingency
How are finality and contingency to be related at the cosmic level? The best-known authors dealing with evolution tend, as we have seen, to consider them antithetical*(27). But it is not only evolutionary biologists who are so quick to judge. Simpson, for example, points out:
"Adaptation is real, and is achieved through a progressive and managed process. The process is entirely natural in its operation. This natural process achieves the aspect of purpose without the intervention of anyone to propose; and it has produced a vast plan without the concurrence of a planner. It may be that the initiation of the process and the physical laws under which it runs had an end, and that this mechanistic mode of realising a plan is the instrument of a Planner - but of this still deeper problem the scientist cannot speak as a scientist"* (28).
Simpson speaks of "long and continuous trends" which "are instigated by natural selection", where "creative natural selection" is "the director, the pseudo-final factor of adaptation"; and he warns, however, that "it is not always the decisive factor in evolution and never acts alone"* (29). Thus, trends can be interrupted, hence his insistence (as we have seen) that the course of evolution cannot be foreseen. Although evolution is "a largely deterministic process", the factors that have determined the emergence of human beings are so hidden and special that while "the emergence of man was inevitable under the precise conditions of our history in fact, this makes it all the more impossible that the same should happen anywhere else"* (30). In some sense, however inevitable, no finality could intrude: "if evolution is the divine plan for creation - a proposition that a scientist, as such, should neither deny nor affirm - then God is not a finalist"* (31). Somehow there is a plan, but no "finality".
Gould would oppose this talk of plans and tendencies, and would emphasise the fragility of the line leading to the human, a topic on which he and Simpson would agree agreement. His own sympathies, he reveals, lie with the tentative solution Darwin once offered, in his correspondence with Asa Gray, to the dilemma of how God could permit the suffering found everywhere in non-human nature: perhaps one might hold that the details of nature's workings are subject not to law but to chance. Consequently, God would be manager of legality, with its suggestion of finality, but not of chance events. The arrival of homo sapiens is "a terribly improbable evolutionary event", Gould stresses. It is a "contingent detail" in the history of the cosmos, something that might well not have happened, something that therefore (Gould implies) cannot be attributed to a purpose. Nevertheless, "we can still expect finality, or at least neutrality, from the universe at large"* (32).
The rather partial suggestion of both authors is thus that perhaps there is enough legality in the universe, despite the predominance of contingency, to sustain some subject defence of finality at the level of the cosmos. But how? For a possible answer we could go back to an objection interposed by Simplicius, the Aristotelian, to Salviati, Galileo's spokesman, in the great Dialogue on the two great systems of the world (1632). If Copernicus were right in the motion of the earth around the sun, a deviation from parallax should be noted in the relative position of the stars. But none is noticed. The alternative is that the stars are at an enormous distance from us. But then, what are these big spaces for, aren't they "superfluous and futile"? To which Salviati replies that God may well have other plans in mind besides the care of the human race. And in any case: "It is foolhardy for our weakness to attempt to judge the reasons for God's acts"* (33). Good committee!
But suppose we were to raise this objection again today. Our universe, as we now know, is far more vast than Copernicus could ever dream of; space and time are beyond the limits of human imagination. Does this not imply a difficulty for the theist? Perhaps not. Perhaps not. Can it not be said that these vast spaces populated by billions of galaxies that have developed over billions of years may have been necessary for the cosmos to naturally produce human life somewhere, once or many times? The contingency of a single evolutionary line could thus be overcome by the vastness of the cosmic scale. Evolutionary biologists are divided, as we have seen, on whether, on an evolutionary basis, a life considered human in the broad sense should arise somewhere in that myriad of planetary systems. But, assuming for the moment an affirmative answer to this question, the vast space of evolutionary possibilities would then make it possible to maintain that there could be here a cosmic purpose on the part of a Creator, a purpose which would not be suppressed by the contingency of particular evolutionary lines.
If God is conceived of as a Creator subject to temporality and whose knowledge of the future depends on his knowledge of the present, this mode of submerging contingency to achieve a distant end would be appropriate. Of course, it presupposes that human life would inevitably arise in a universe of this general subject , if it is sufficiently old and extensive. And this, some theists would object, we do not know. subject There may well be steps in the process that would require some "special" action of God for them to take place. In a recent essay, Peter van Inwagen observes:
"Since the physical world appears to be indeterministic, it is plausible to suppose that there are many states of affairs which are not part of the divine plan and which, moreover, cannot be traced to the free decisions of created beings. I doubt very much that when the universe was, say, 10-45 seconds old, it was inevitable that the earth, or even the Milky Way galaxy, would exist. Therefore, these objects, so important from the human point of view, are not part of God's plan, or at least they are not unless their origin is due to a miraculous intervention of God in the course of the physical world's development relatively late stage. I see no reason as a theist, or even as a Christian, to believe that the existence of human beings is part of God's plan"* (34).
Realising that this insinuation is likely to disturb the average Christian, van Inwagen adds a significant nuance: "I am sure that the existence of animals made in the image of God - that is, rational animals having free will and the capacity to love - is a part of God's plan". Although he sees "no reason to believe", on theological instructions , that God had in his plan this particular race of human beings, on the same basis he is sure that some race of human subject was in God's plan*(35).
Like evolutionary biologists who consider the contingency of the human line an obstacle to describing the emergence of humanity as a consequence of a purpose, van Inwagen takes contingency very seriously as a negative sign for attributing some feature of the universe to the divine plan. (Note the "therefore" in the middle of the quoted passage). But he suggests a way in which this contingency can be, shall we say, transcended, a way that does not depend on the cosmic scale. God can intervene miraculously in the causal process to secure a particular effect, in which case the effect, despite the appearance of contingency from the scientific point of view, would still be result of a plan, God's*(36). Thus, there is here a second way in which the contingency of the evolutionary process leading to man could be reconciled with the claim that the emergence of man on earth is nevertheless part of the divine plan for the cosmos.
Van Inwagen does not develop this hint of a "special" action of some subject on the part of the Creator in the crucial steps of development of life on earth. But many others have done so, and from very different points of view. The most radical claim would be that of the advocates of so-called "creation science", who postulate a more or less literal interpretation of the Genesis account of the origin of man*(37). A much more nuanced view would be that of Alvin Plantinga, who argues for the inadequacy of the current theory of evolution to account for several stages in the development of life, starting with the appearance of the first living cell, and the consequently greater plausibility, from a Christian point of view, of a "special creation" by God at some crucial steps along the way*(38). And a very different perspective would be that of John Polkinghorne, who finds in chaos theory and quantum theory the guarantee of a "slackness" in physical processes that would be excluded in the Newtonian worldview. This leads him to suggest that God can operate in the ontological "holes" thus provided, communicating certain information without altering the amount of energy. In this way, God could accomplish the ends of Providence without the need for miracles, in the sense of an observable deviation from the normal order of nature* (39).
These three treatments of divine action in the cosmic process are in fundamental disagreement, particularly in considering the role to be played by natural science in illuminating the course of that process. But they are implicitly of agreement in attributing finality at the cosmic level to a "special" action of some subject on the part of the Creator within the cosmic process. I will not discuss here the merits or demerits of these views. Instead, I propose to examine an alternative way of dealing with the challenge that contingency offers to our hopelessly earthly notions of a Creator as Being whose action is guided by "purposes" and who "makes plans". Might chance not be one way in which God makes things happen? Does contingency preclude there being a plan on the part of an agent who need not rely on a knowledge of the present to plan for future consequences?
5. Eternity and teleology
In the preceding discussions, we have accepted some simple and probably plausible assumptions about the relationship between time and teleology. But what if we were to question them, what if the Creator were to remain absolutely outside the temporal process? This, after all, has been the dominant view of creation in the Christian tradition since the days of St. Augustine. Admittedly, it has been questioned in more recent times, but it retains great favour among Christian theologians. Would this perspective change anything in our treatment of the meaning of the evolutionary sequence? First, a brief summary of the perspective itself.* (40)
Augustine saw God not as a demiurge shaping an independently existing subject or as the prime mover manager of the movements of a world whose natures were not His creation, but as a Creator in the sense plenary session of the Executive Council, a Being from whom the existence of everything proceeds. This Being cannot act under conditions, like that of the Greek philosophers. Temporality is the first and most obvious condition of the created world, a sign of its dependent status. A temporal being exists only in the present, with no certain access to its past or its future. Its past is no longer; its future is not yet. So even if both past and future are somehow constitutive of what this being is, in a real sense they do not exist. This being is evidently lacking, incomplete.
The Creator on whom the universe depends for its existence cannot be limited in this way. Time is a condition of the creature, a sign of dependence. It is created with the creature itself; in bringing into being a changing world, God brings into being time, the condition of change. The act of creation is unique, and in it what is past, present or future from the creature's perspective comes as a single totality from the Creator*(41). God is not part of the temporal sequence that the act of creation puts into being; God is not just another temporal thing among temporal things. The Creator is "outside" created time, though the metaphor is imperfect. To call God "eternal" is not a way of saying that God is without beginning or end, like Aristotle's universe*(42). "Eternal" does not mean endless duration; it means that temporal notions simply do not apply to the Creator as such. Nor does it mean "static", as nineteenth-century critics thought. In a famous expression, Boethius put it in lapidary terms: "eternity is the complete, simultaneous and perfect possession of life without limit. God's life transcends the kind of dispersion which is the first characteristic of the creature; it is not subject to the division which the passage of time would require.
Creation and conservation merge in this perspective, as do immanence and transcendence. Creation was not only a moment of origination of the cosmos long ago, although we sometimes speak of it as such since the first moment seems to appeal especially to a transcendent cause. Creation continues at every moment, and at every moment has the same relationship of dependence on the Creator. God transcends the world; the Divine Being is not at all dependent on the world for its existence, nor does it require it as a complement. But the Creator is also immanent in all being and at all times, maintaining it in being. God knows the world in the very act of creating it, and therefore knows the cosmic past, present and future in a unique and immediate knowledge*(44). God knows the past and future of every creature, not from report or by prediction, as another creature would, but in the same direct way as he knows the creature's present. When we speak of God's "foreknowledge", the future "pre" refers to our creaturely framework , within which the distinctions between present, past and future are real. On God's side, however, there is only knowledge, the knowledge proper to a doer who is not limited by these distinctions.
This is quite well known, of course. It is very conceptual, as is inevitably the philosopher's speech about God. It is no more than an exploration of an initial postulate concerning the act of creation, when such an act is understood as a bringing into existence and a maintaining in existence, both of which are outside the realm of our experience. How might this perspective be supported? How does it meet the two main objections already anticipated by Augustine? Namely, can this way of conceiving the work of creation be made compatible with the reality of human freedom, and does it not burden the Creator with the responsibility for the manifest evils of the history of the cosmos? I leave aside these familiar and problematic questions to concentrate on a limited but perhaps more tractable topic : how does one reconcile the apparent annulability of the evolutionary line leading to homo sapiens with the idea that the act of creation is a unique and timeless action on the part of God?
What I want to argue is that, from the perspective of the traditional doctrine of the eternity of God, both Christian evolutionists who have assumed that the Creator's purposes can be realised only according to laws and in a more or less predictable way, and those who, on the contrary, deduce from the contingency of the evolutionary process the lack of finality and meaning of the universe in general, are wrong. Our notions of teleology, finality and plan are conditioned by the temporality of the world, in which plans unfold gradually and processes come to completion in an orderly fashion. A Creator who puts everything in being into a single act from which the whole temporal process flows does not rely on the regularity of the process to know the future condition of the creature or to achieve its ends. God's knowledge of how a status will develop later is not discursive; God does not infer from a prior knowledge how the situations of that subject usually develop. It does not matter, therefore, whether the emergence of homo sapiens is the inevitable result of a constant process of complexification extending over billions of years, or whether it arises through a series of coincidences that would make it completely unpredictable from a human causal point of view. Either way, result is the work of God, and from a biblical point of view it could well be said to be part of God's plan.
Obviously, terms like "plan" change meaning when the temporal element is absent. God planning and the event taking place are identical. There is no interval between decision and execution. Thus, the character of the process which, from our perspective, separates initiation and completion is of no relevance to whether or not a plan or finality on the part of a Creator is implied. The reference letter to a "cosmic finality" in this sense does not imply design in the traditional sense. That is, it does not point to the details of the process or the result that specifically require the intervention of a mind. There is nothing in the evolutionary process itself that would lead one to recognise in it the deliberate action of a Planner. It does not look like the subject process that human designers would employ to achieve their ends. When critics of the Christian idea of the history of the cosmos conclude, therefore, that we live in a universe devoid of purpose, what they are pointing to is this absence of an independently recognisable design.
But the Creator is not a designer in this temporal sense. And the contingency or otherwise of the evolutionary sequence does not affect whether the created universe includes finality or not. To affirm the reality of the finality of the cosmos in this context assumes that the universe depends for its existence on an omniscient Creator. It does not mean that we are aware of that finality, although the traditions of the Torah, the Bible and the Koran would all imply recognition of at least some of it. Only insofar as such acknowledgements were possible could one grant that cosmic finality constitutes a certain subject of teleology (remembering that "teleology" alludes to specific modes of explanation). When, in the Confessions, Augustine looks back over his life and finally recognises a Providence working through all contingency, it is to a teleology of this subject that he refers.
Relating plan and Providence in this way gives rise to many other questions, of course. One would have to distinguish in particular between God's allowing and God's intending something to happen*(45). But the answers to these questions, important and even crucial as they are, do not affect the argument of this essay: that if one maintains the ancient doctrine of the eternity of God, the contingency of the evolutionary process leading to the emergence of homo sapiens does not affect the Christian belief in a special destiny for humanity.
- See I.S. Shklovskii and C. Sagan, Intelligent Life in the Universe, Holden-Day, San Francisco 1966, ch. 29.
- InPersons: A Study of Possible Moral Agents in the Universe (Herder and Herder, New York 1969), Roland Puccetti draws on Sagan's analysis to conclude that "a correct analysis of the concept of personhood, combined with the not unreasonable belief in the existence of extraterrestrial natural persons, actually undermines the Christian belief in God" (p. 143). His argument is that since the total issue of communities of persons in all the galaxies could be as many as 108, and since God could not be incarnated simultaneously in more than one person, there would be no way for God to be incarnated in all these communities over the entire time span of the universe, as Christian faith would seem to require. The argument is fascinating but excessively porous. See McMullin, Persons in the Universe, "Zygon" 15 (1980) 69-89.
- See McMullin, Estimating the Probabilities of Extraterrestrial Life, "Icarus" 14 (1971) 291-294.
- The Origin of Species, University of Pennsylvania Press, Philadelphia 1959, p. 221.
- P. Teilhard de Chardin, The Phenomenon of Man, Harper, New York 1965, pp. 151, 149, italics in original.
- G. Gaylord Simpson, This View of Life, Harcourt, Brace and World, New York 1964, p. 189.
- Jacques Monod, Chance and Necessity, Knopf, New York 1971, pp. 112-113. Italics his.
- Ibid., pp. 169-170.
- Ibid., pp. 119, 124, 127.
- S. J. Gould, Eight Little Piggies, Penguin, New York 1993, p. 77.
- Ernst Mayr, one of the foremost exponents of synthetic theory, argues that an apparently discontinuous sequence of this subject can easily be incorporated into a broadly Darwinian view of evolutionary change. Recall that he had already indicated the need for such a modification in part of his early work (Toward a New Philosophy of Biology, Harvard University Press, Cambridge (Mass.) 1988, ch. 26: "species evolution through punctuated equilibrium").
- S. J. Gould, Wonderful Life, Harvard University Press, Cambridge (Mass.)1989, p. 318.
- Wonderful Life, p. 318.
- See, for example, the extensive polemic in Daniel Dennett, Darwin's Dangerous Idea, Simon and Schuster, New York 1995, chap. 10.
- Wonderful Life, pp. 291, 289.
- Theodosius Dobzhansky, Chance and Creativity in Evolution, in F.J. Ayala and T. Dobzhansky (eds.), Studies in the Philosophy of Biology, MacMillan, London 1974, pp. 309, 331.
- Chance and Creativity, pp. 318, 329.
- Francisco Ayala, The Concept of Biological Progress, in Studies in the Philosophy of Biology, pp. 339-356.
- See Timothy Lenoir, The Strategy of Life, Reidel, Dordrecht 1982.
- See William Wimsatt, Teleology and the Logical Structure of Function Statements in Studies in the History and Philosophy of Science 3 (1972) 1-80; Larry Wright, Teleological Explanation: An Etiological Analysis of Goals and Functions, University of California Press, Berkeley 1976. For a discussion of the pros and cons, see William Bechtel, Teleological Functional Analysis and the Hierarchical Organization of Nature, in N. Rescher (ed.),Current Issues in Teleology, University Press of America, Lanham MD 1986, pp. 26-48.
- Contemporary discussions of teleology vary widely in the taxonomies they propose. See, for example, Wolfgang Kullman, Different Concepts of Final Cause in Aristotle, in Allan Gotthelf (ed.), Aristotle on Nature and Living Things, Mathesis, Pittsburgh 1985, pp. 169-176; Marjorie Grene, Time and Teleology, ch. 9 of The Knower and the Known, University of California Press, Berkeley 1974; Ernst Mayr, The Multiple Meanings of Teleological, ch. 3 of Toward a New Philosophy of Biology.
- Dennett, Darwin's Dangerous Idea, pp. 320-321.
- See John M. Cooper, Hypothetical Necessity and Natural Teleology, in Aristotle on Nature and Living Things, pp. 151-167.
- Aristotle leaves unexplained why natures should act in this orderly way. Is it simply the case that the world is like this, or is there some prior reason why finality should govern nature in the way it does? Aquinas takes the analysis a step further: "The fifth way is taken from the government of the world. We see that things that lack knowledge, like natural bodies, act for an end, and this is evident because they always or almost always behave in the same way in order to obtain the best result. Thus, it is clear that they achieve their end not by chance but according to a design. Now that which lacks knowledge cannot move towards an end, unless it is directed by some being endowed with knowledge and intelligence...". (Summa Theologica, I, q.2, a. 3c). This shifts the mode of explanation to one of a teleological nature in the first sense mentioned above.
- This is reflected in the way evolutionary biologists themselves describe adaptation, using expressions such as "in order to" (recall the Aristotelian "that for the sake of which"). Thus, for example, "Perhaps flowers have evolved to attract bees from other plants", degree scroll from a recent article in the New York Times.
- Bechtel points out some difficulties in the analysis offered by Wimsat and Wright, but argues that they can be overcome ("Functional analyses"). And the natural selection process has by no means, as we have seen, the constancy described by Aristotle in his treatment of teleology. Moreover, it is only part of the explanation, other factors (mutation, drift, environmental change) being "vagaries" of nature in the Aristotelian sense, and thus in contradiction with teleological explanations. It is interesting to note that when Aristotle defines chance (tuchê) in Book II of the Physics, he considers it as an intersection of independent lines of causality, which, when considered separately, are determined.
- Some critics, such as Dennett and Dawkins, are not fundamentally thinking of the topic of contingency when they reject the resource to the Creator as a means of anchoring the finality of the cosmos. Their argument is rather that the Creator is a "lazy wheel", that the neo-Darwinian argument, allied with the dominant astrophysical argument in cosmology, needs no supplementation, no "skyhook", to use Dennett's metaphor. See Daniel Dennett, Darwin's Dangerous Idea; Richard Dawkins, The Blind Watchmaker, Norton, New York 1987.
- Simpson, This View of Life, p. 212.
- This View of Life, p. 210.
- This View of Life, p. 268.
- This View of Life, p. 265.
- Wonderful Life, p. 291.
- Dialogue Concerning Two Chief World Systems, trans. by Stillman Drake, University of California Press, Berkeley 1953, pp. 367-368.
- Peter van Inwagen, The Place of Chance in a World Sustained by God, in T.V. Morris (ed.), Divine and Human Action, Cornell University Press, Ithaca 1988, p. 225.
- At first glance, it might seem that the distinction van Inwagen makes here is the same as the one I have discussed: the contingency of the particular evolutionary line leading to humanity is in contrast to the inevitability of finding beings of subject human somewhere in such a vast universe. But, in fact, this is not the basis of the distinction he has in mind. He certainly rejects the implication that in such a vast universe such beings should appear. Instead, he suggests that it is sufficient for God to aim at the general end of bringing life somewhere in the universe, while the appearance of this particular race, not being "physically inevitable", is not necessarily to be considered part of the divine plan.
- Van Inwagen uses the term "miraculous" in a broader sense than usual to include, for example, physical sequences that would be imperceptible to us. And he warns us against accepting the term "intervene" to suggest that God is in some sense outside the process; we simply lack a word to signify a "special" action of God to produce an effect outside the ordinary course of nature. (I thank Professor van Inwagen for our discussion of the ramifications of this essay). If God were to "intervene" in a causal sequence, it would, of course, have to be in a particular sequence. So (as van Inwagen supposes; see hisDoubts about Darwinism, in J. Buell and V. Hearne (eds.), Darwinism: Science or Philosophy, Foundation for Thought and Ethics, Richardson TX, 1996, 177-191) if there is reason to think that God intervened to supplement the evolutionary process that would lead to the appearance of the human race on earth, there will also be reason to think that the existence of human beings on earth is part of God's plan.
- See, for example, Henry Morris, Scientific Creationism, Creation-Life Publishers, San Diego 1974.
- See Alvin Plantinga, When Faith and Reason Clash: Evolution and the Bible, in "Christian Scholar's Review" 21 (1991) 8-32. Two critical responses to this essay appear in the same journal issue : Howard J. Van Till, When Faith and Reason Cooperate, pp. 33-45; Ernan McMullin, Plantinga's Defense of Special Creation, pp. 55-79. Plantinga, in turn, replies to them: Evolution, Neutrality, and Antecedent Probability, pp. 80-109. One more comment: Ernan McMullin, Evolution and Special Creation, "Zygon " 28 (1993) 299-335.
- See John Polkinghorne, Science and Providence: God's Interaction with the World, Shambhala, Boston 1989. For a critical assessment of his proposal, see Steven CRAIN, Divine Action and Indeterminism: On Models of Divine Agency that Exploit the New Physics, thesis doctoral, Ann Arbor Microfilms, Ann Arbor 1993.
- See, for example, Alan G. Padgett, God, Eternity, and the Nature of Time, St. Martin's Press, New York 1992, ch. 3: The doctrine of Divine timelessness: A historical sketch. I am grateful to David Burrell and Fred Freddoso for our discussions of the issues raised in this section.
- How to relate the temporality of the creature to the eternity of God without making temporality unreal (by assuming that the future already exists) or rendering God quasi-temporal has been a challenge for philosophers from St. Thomas to the present day. See Eleanor Stump and Norman Kretzman, Eternity, "Journal of Philosophy" 78 (1981) 429-459.
- See G.D. Yarnold, Everlasting or eternal?, ch. 9 of The Moving Image, Allen and Unwin, London 1966, pp. 139-152; Brian Davies, A timeless God?, "New Blackfriars " 64 (1983) 218-224; Julie Gowan, God and timelessness: Everlasting or eternal?, "Sophia " 26 (1987) 15-29.
- The consolation of Philosophy, 5.6.
- Aquinas undertakes a formal defence of the thesis that God knows contingent futures (Summa Theologica, I, q. 14, a. 13). These things are contingent in relation to their antecedent physical causes, which is why temporal creatures like us, whose judgments about the future depend on the knowledge of such antecedent causes, can only conjecture their contingent effects. But God knows these effects directly in his own timelessness as Creator; the act of bringing them into existence has no temporal dimension. Some of the analogies St. Thomas offers here require a cautious construction: "He who sees the whole road from a height, sees at once all who walk along it" (a. 13, ad 3); "His gaze travels the stretch from eternity to all things as present" (a. 13, c.). These analogies might suggest that our inability to predict a contingent effect is simply due to our lack of a proper point of view: the various events that are taking place at this very moment turn out to be beyond our grasp. This in turn could be taken to imply that the future is already established, that it is only that our ability to know it is overtaken by the task. But contingency is real, as St Thomas makes clear elsewhere. God knows contingent things that are future for us not as a spectator would know the features of a predetermined landscape but rather as a doer, a unique subject of a doer who respects contingency in the occasional connections between things made. The discussion on how God knows contingent futures intensified after the time of St Thomas, particularly on the point of how it could be reconciled with the reality of human freedom of will. It reached its climax at cima with the famous "de auxiliis" controversy at the end of the 16th century between the Dominicans, defenders of Báñez, and the Jesuits, defenders of Molina. For a study of the subtleties to which this long discussion gave rise, see William L. CRAIG, The Problem of Divine Foreknowledge and Future Contingents from Aristotle to Suarez, Brill, Leiden 1988.
- topic For a comprehensive treatment of this and related topics, see, for example, the essays in Divine and Human Action, cited above.