Does evolution have a moral and/or spiritual dimension? The answer depends on how you define the words ‘moral’ and ‘spiritual’ and, for that matter, ‘dimension’. Certainly the words can be defined broadly enough so that the answer is yes.

For example, people in all parts of the world have moral systems of one kind or another. And these moral systems are undergirded by certain common features of the human mind: the sense of justice (the intuitive feeling that good deeds should be rewarded and bad punished); the conscience, including such feelings as guilt; various feelings that inspire people to do things that get labelled as moral or immoral – feelings ranging from hatred to compassion; and so on.

In this sense, humankind has a ‘moral dimension’ – that is, human beings around the world exhibit the raw materials necessary for a moral system. Since evolution created human beings, it must have given them, at the very least, the capacity for these raw materials. In that minimal sense, evolution by natural selection can be said to have a moral dimension: it has properties that, in the case of the human species at least, gave life the capacity for a moral system.

Can evolution have a moral dimension in a stronger sense than this? And can it in any strong sense have a spiritual dimension? An affirmative answer to both these questions is plausible, but before making that argument a broader question needs to be asked: Does evolution have a direction?

I believe so. I think natural selection tends by its nature to drive life to higher and higher levels of complexity and intelligence. That doesn’t mean it drives all lineages in that direction, or that complexity and intelligence never decline in the course of evolution. But it does mean that the ‘outer envelope of complexity’ and the ‘outer envelope of intelligence’ – the levels of complexity and intelligence embodied in the most complex and intelligent species on the planet – tend to grow in the long run, and that the reasons for this growth are deeply engrained in the dynamics of natural selection.

This view is, of course, not universally shared. The best known proponent of the alternative view was the late palaeontologist Stephen Jay Gould, who persistently stressed the directionlessness of evolution, and minimised the significance of any apparent directionality. But it has now been demonstrated that Gould’s argument suffers from several fallacies and omissions, most notably his inattention to the importance of ‘arms races’ – a dynamic in which competing species (for example, a predator and prey species) get locked into a positive feedback cycle of ongoing adaptation that leads to growing complexity in both lineages.1

In my own critique of arguments that depict evolution as directionless, I’ve gone beyond merely asserting that high levels of ‘complexity’ and ‘intelligence’ – in some generic sense of those words – were extremely likely outcomes of evolution. Furthermore I’ve argued that the specific type of intelligence characteristic of the human species was a quite likely eventual outcome. That doesn’t mean, of course, that the particular lineage that led to the human species was a likely evolutionary winner; effectively random forces, such as droughts and other environmental catastrophes, can wipe out any particular lineage; in that sense evolution is a highly contingent process. Rather, my contention is that certain key properties were likely evolutionary winners. The various traits that form the core of human intelligence (linguistic ability, for example) or that contributed to the evolution of human intelligence (grasping appendages, for example) – were likely, sooner or later, to wind up together in one species or another.

This set of traits – key elements in the evolution of human intelligence – include some with clear relevance to morality: ‘kin-selected altruism’ (which, in a complexly sentient species, seems to be accompanied by such emotions as love and compassion and, on occasion, guilt); and ‘reciprocal altruism’ (which, in a complexly sentient and intensively social species, seems to entail a ‘sense of justice’ – an intuitive sense that good deeds should be rewarded and bad deeds should be punished).

I can’t, in this short space, recapitulate my argument that these various traits were likely outcomes of evolution (the argument occupies a full chapter of my book Nonzero). Certainly, though, it is relevant that all of these traits have evolved, independently, more than once in the course of organic evolution. In any event, for now let me just make the point that, if you accept my argument about the likelihood of these outcomes, then evolution has a moral dimension in a stronger sense than the sense described above. That is, evolution didn’t just give human beings the capacity for the ingredients of a moral system, such as love and hate and guilt and a sense of justice; and evolution didn’t just give human beings a positive genetically based disposition toward these ingredients of a moral system, though certainly one implication of my argument, and indeed of mainstream evolutionary psychology; evolution was very likely all along eventually to create a species that possessed these genetically based dispositions. In that fairly strong sense, I believe, evolution has a moral dimension: the ingredients of a moral system were implicit in evolution all along; their eventual expression was highly likely, in one species or another.

That is not to say, by the way, that genetic evolution features moral progress. It is just that evolution naturally leads to a species with the impulses that undergird a moral system – such impulses as love, hate, guilt and moral judgement and so on. Our lineage may or may not have become in some sense ‘more moral’ over time, but it has certainly become more moralistic; Homo sapiens naturally pass moral judgement on others. Our lineage has also become more morally reflective; Homo sapiens naturally question whether their behavior is good or bad, however lamentable their socially conditioned definitions of ‘good’ and ‘bad’ may sometimes be. And we Homo sapiens also, by our nature, provide plenty of subject matter for moral judgement and reflection, because we are naturally possessed with a tendency to exhibit, in intense form, love and hate, commitment and betrayal, and so on.

Arguments about the directionality of evolution are inherently speculative. You can’t rewind the tape and replay evolution with a few variables altered to see if, once again, you wind up with a species smart enough to hold conferences in Sweden. However, I do think that the evidence for directionality of the sort I’m describing – and hence evidence that evolution has a ‘moral dimension’ – is stronger than has been acknowledged by many who discuss the question of directionality in evolution. Few scientists appreciate how natural an outgrowth of organic evolution morality is.

One exception is the evolutionary psychologist Steven Pinker, whose recent book The Blank Slate (Viking, 2002) touches on the issue of moral directionality in evolution. In any complexly sentient social species imbued by natural selection with the mental and emotional equipment to help it play ‘non-zero-sum’ games – that is, to help members of the species interact co-operatively with other members, even when not closely related to them – certain properties are likely to emerge, Pinker believes. For example, ‘No creature equipped with circuitry to understand that it is immoral for you to hurt me could discover anything but that it is immoral for me to hurt you.’ Thus Pinker suggests that in this sense, evolutionary psychology may add credibility to the philosophical position known as ‘moral realism’. Moral realism is the belief that basic moral truths – such as ‘one good turn deserves another’, or ‘evil-doers should be punished’ – may in some sense exist ‘out there’ in a Platonic realm, in the same sense that such mathematical truths as two plus two equals four do. ‘Our moral sense may have evolved to mesh with an intrinsic logic of ethics rather than concocting it in our heads out of nothing’, Pinker writes.

The question of whether evolution has a spiritual dimension is (even) more intractable than whether it has a moral dimension. One reason is that the word ‘spiritual’ is even vaguer than the word ‘moral’. For the purposes of argument, let’s interpret the word ‘spiritual’ the way many theists might: that evolution by natural selection has a spiritual dimension if it has a purpose – if it was designed by some external, perhaps divine, force or agent for the purpose of reaching some end. Is there any evidence of such design?

Please don’t confuse this question with those raised by the so-called ‘intelligent design’, or ID, movement. ID proponents believe that natural selection is by itself inadequate to account for human evolution. In contrast, I accept natural selection as an explanation for human evolution and am raising the further question of whether natural selection could itself have been designed to achieve some end – whether, for example, natural selection may be an instrument of divine creation.

This is a question that, by its very nature, is extremely speculative. But I do think that there is more reason than commonly acknowledged to suspect that natural selection is a product of design.

To begin with, the very directionality described above is (at least tentative) evidence for design. Obviously, a process which systematically moves toward something is more likely to have been designed to reach some end than a process that doesn’t systematically move toward anything.

In a more technical sense, one could look at criteria that philosophers have developed for determining whether a system is purposeful. Many such criteria have been nominated. Here is my favourite: a system has the hallmarks of purpose if it (a) moves toward some (posited) goal (i.e., has discernible direction); (b) persists in that direction even if external perturbations deflect it from this direction temporarily; (c) achieves that persistence via information processing – via positive and negative feedback. I’ve argued (see Nonzero) that evolution by natural selection fulfills those criteria. It heads in the direction of complexity and intelligence (in the sense defined above); it flexibly persists in that direction even if afflicted by such obstacles as environmental catastrophe; it achieves this flexibility by a kind of information processing: it sends out bits of information (new genes) whose proliferation amounts to positive feedback (signifying adaptive compatibility with the altered environment) and whose extinction amounts to negative feedback (the lack of such compatibility).

There is another, more intuitive, way of making largely the same point. Many evolutionary biologists speak of organisms as having a ‘purpose’. That is, organisms were ‘designed’ (by the process of natural selection, not by a conscious designer) to pursue a ‘goal’ (spreading their genes) and to do things subordinate to that overarching goal (eat food and grow to adulthood, say). Such biologists might watch an organism growing coherently toward adulthood (growing in biological complexity, in information processing, in richness of sentience), note its ability to sustain that growth notwithstanding environmental perturbations, and opine that this flexible directionality is a manifestation of the ‘purpose’ it was ‘designed’ for. I submit that the growth of the Earth’s ecosystem – culminating (so far) in the evolution of a species intelligent enough to assume stewardship of the whole ecosystem, to serve in effect as the planet’s brain – is more analogous to this process of an organism’s maturation than is commonly appreciated.

To be sure, there is lots of contingency in the evolution of the Earth’s ecosystem. Then again, there is more contingency in the maturation of an organism than most people realise. Whether any given stem cell will become, say, a cell in the eye or in the lungs depends on unpredictable environmental forces. Still, the fact that the properties of eyesight and respiration will eventually appear – whatever lineage of cells happens to embody them – is predictable with a high degree of confidence. Similarly, I contend that such properties as a human-level intelligence were likely to appear via organic evolution, even if the particular lineage that would embody them was unpredictable, and dependent on environmental contingency.

If indeed an organism’s coherent growth toward complexly integrated functionality is evidence of design and purpose, then why should the ecosystem’s coherent growth toward complexly integrated functionality not be counted thus?

Of course, in the case of the organism, the designer and the purpose turn out to be fairly mundane: the designer is the blind mechanism of natural selection, and the purpose is the transmission of genetic material. Is there any reason to believe that any designer or purpose that may lie behind natural selection is any less mundane? To put the question another way: some people might grant that the process of evolution by natural selection has some of the hallmarks of overarching purpose, yet insist that overarching purpose by itself doesn’t qualify as a spiritual dimension of evolution. They might ask whether there is any evidence that the purpose is of the sort traditionally associated with the divine.

Here the argument grows more speculative still. But I do think there is scattered evidence of this sort.

First, there is the existence of consciousness (by which I mean sentience – subjective experience). The existence of consciousness is a much deeper mystery than most behavioural scientists realise. According to a common philosophical position known as ‘epiphenomenalism’ (a position implicitly embraced in many behavioural science circles), sentience is functionally superfluous; subjective experience shouldn’t in theory be necessary for any kind of human behaviour, including even such behaviours as speech. Given that subjective experience is (arguably) what gives meaning to life, this mysteriousness of its existence is, I would argue, theologically suggestive.

Second, there is the existence of the aforementioned ingredients of morality. The human penchants for compassion and hatred, for altruism and violence, for reflective choice, for moral judgement, and so on – such things are traditionally associated with the kinds of divine ‘purpose’ that theologians have traditionally posited. (This doesn’t mean that hatred and violence are themselves divine, or even good – just that they are basic features of the landscape of good and evil with respect to which the divine is typically defined.) If indeed, as I argue, these features were likely outcomes of evolution, that could be taken to lend a kind of credence to the speculation that evolution has hallmarks of divine design.

Third, there is directionality in human cultural evolution. Various people (dating at least back to Lewis Henry Morgan, author of the 1877 book Ancient Society) have argued that an observed trend in the evolution of human technologies and ideas – toward larger and more complex societies, from Stone Age hunter-gatherer villages to the modern system of interdependent nation states – is a natural result of the basic dynamics of cultural evolution. What’s more, this growth in the breadth and depth of social complexity seems to have been accompanied by an expansion of the ‘moral compass’ (an historical trend that the philosopher Peter Singer has called ‘the expanding circle’ in his book of that name). That is, whereas 12,000 years ago compassion and decent treatment rarely extended beyond the confines of the village, and even more rarely beyond one’s ethnic group, in economically modern nations most citizens agree that people of all religious and ethnic groups deserve certain basic human rights. If indeed this expanding moral compass is, as I argued in Nonzero, embedded in the very direction of cultural evolution, then one might well consider that fact evidence of divine purpose. (I attribute the expansion of the compass largely to the growth of economic and other forms of interdependence among the world’s peoples, whereas Singer’s explanatory emphasis is somewhat different.)

To summarise: Both biological and cultural evolution have exhibited a direction; both have shown a general trend toward higher levels of complexity. Whether this trend was ‘in the cards’ – highly likely by virtue of the basic dynamics of these evolutionary processes – is a question over which reasonable people can disagree, given the inherently speculative nature of hypothetical arguments about the past. But I’ve argued – briefly here and at length elsewhere – that there is more reason than commonly appreciated to believe that this directionality indeed flows from the essential logic of evolution.

In addition to exhibiting a movement toward complexity, both evolutionary processes, I believe, exhibit certain forms of ‘moral’ directionality. Biological evolution was likely all along to create the raw material for a moral system, and human cultural evolution has, ever since the stone age, been likely to expand the scope of moral systems, so that today people separated by great distances, and by ethnic or religious cleavages, often treat one another with respect and tolerance, and even exhibit far-reaching compassion and generosity. (The tremendous amount of ethnic and religious strife in the world today shouldn’t be allowed to obscure the fact that, viewed in historical perspective, we currently live in times characterised by relatively high degrees of intercultural tolerance.)

As with the question of the evolution of complexity, reasonable people can disagree over how likely this moral direction was to emerge (especially given that, in the case of biological evolution, only one lineage has so far produced a species capable of extended moral reflection). But – again, as with the question of the evolution of complexity – I think that this evolutionary trend was more likely than is commonly appreciated. And to the extent that such a moral dimension indeed seems to have been inherent in the evolutionary process, then notions of a spiritual dimension of evolution are commensurately strengthened.

This essay originally appeared in Consciousness, Genetics and Society: Perspectives from the Engelsberg seminar, Axess, 2002.