Chapter 1

Eternity and Evolution

Evolution in an eternal world

Science inherited a dual vision of the world from the nineteenth century: on the one hand a great evolutionary process on Earth, and on the other, the physical eternity of a mechanistic universe. In this vision all the matter and the energy in the cosmos were eternal, and everything was governed by eternal laws of nature.

From this dual perspective, life evolved on Earth within a physical eternity. The evolution of life made no difference to the fundamental realities of the physical universe. Nor would the extinction of life on Earth. The total amount of matter and energy and electric charge remained exactly the same, and so did all the laws of nature. Life evolved, but fundamental physical reality did not.

This double worldview has become deeply habitual, and in many ways continues to shape scientific thinking. In this chapter we examine this conventional split in more detail, and see where it has already begun to be transcended. What is emerging in its place is an evolutionary vision of reality at every level: subatomic, atomic, chemical, biological, social, ecological, cultural, mental, economic, astronomical and cosmic.

Physical eternity

The mechanical universe of nineteenth-century physics was eternal, a vast machine governed by eternal laws.

The idea of the world machine of physics started life in the seventeenth century. The machine was thought to have been made by God, set in motion by his will, and thereafter to work automatically in accordance with his immutable laws. Nevertheless, for the first century of its existence, the Newtonian world machine had a persistent tendency to run down. From time to time the celestial clockwork had to be wound up again by God.

By the beginning of the nineteenth century, the theoretical machinery had been perfected and the world became a perpetual motion machine. The machinery was eternal, and it would always go on, as it always had done, in an entirely deterministic and predictable way; or at least in a way that would in principle be predictable by a superhuman all-knowing intelligence, if such an intelligence existed.

For the great French physicist Pierre Laplace and for many subsequent scientists, God was no longer needed to wind things up or start things off. He became an unnecessary hypothesis. His universal laws remained, but no longer as ideas in his eternal mind. They had no ultimate reason for existing; they were purposeless. Everything, even physicists, became inanimate matter moving in accordance with these blind laws.

By the middle of the nineteenth century, the world machine started to run down again. It could not be a perpetual motion machine because, according to the newly formulated laws of thermodynamics, perpetual motion machines are impossible. The universe must be running down towards a final heat death, a state of thermodynamic equilibrium in which the machinery would stop working, never to start again. The machine would run out of steam, and a God who had become an unnecessary hypothesis could not be expected to stoke it up again. Nevertheless, all the matter and energy of the world would endure forever; the remnants of the exhausted machinery would never decay.

The revolutions in twentieth-century physics transcended the old mechanistic metaphors in a variety of ways.1 The indestructible billiard-ball atoms became complex systems of vibrating and orbiting particles, themselves complex structures of activity. The rigorous determinism of classical mechanistic theory softened into a science of probabilities. And spontaneity re-emerged in everything. Even the vacuum ceased to be an empty void; it became a seething ocean of energy, producing countless vibrating particles all the time and taking them back again. ‘A vacuum is not inert and featureless, but alive with throbbing energy and vitality.’2

The world machine of matter in motion was transformed by relativity and quantum physics into a cosmic system of fields and energy. As Einstein conceived of it, the universe existed eternally within the universal field of gravitation. He did not conclude that the universe was essentially constant because of his general relativity theory, but in spite of it.3 He adjusted his equations to endow the universe with an eternal stability:

When Einstein first applied his field equations of general relativity to the cosmological problem he discovered that static solutions were impossible. Since there was at that time no observational evidence to suggest that the Universe was in a non-static state and the philosophical prejudices of centuries underpinned the notion of a changeless background universe, Einstein altered his field equations to include the cosmological constant, L. The Einstein equations with cosmological constant have a static cosmological solution: the Einstein static universe.

John Barrow and Frank Tipler4

Static models of the universe remained orthodox until the 1960s, and many of the habits of thought engendered by the idea of a physical eternity still persist with great power.

Evolution

We also inherited from nineteenth-century science a great evolutionary vision, very different in spirit from the eternal universe of physics. The many kinds of living organisms – centipedes, dolphins, bamboos, sparrows, and millions of other species – have come into being through a vast creative process. The evolutionary tree has been growing and branching spontaneously for well over 3 billion years. We ourselves are products of evolution, and evolution continues at an ever-accelerating pace in the realm of humanity. Societies and cultures evolve, civilizations evolve, economies evolve, and science and technology evolve.

We experience the evolutionary process directly in our own lives: the world around us is changing as it has never changed before. Stretching back behind the changes that we ourselves have seen is the evolution of modern civilization, itself rooted in earlier civilizations and more primitive forms of society. Beyond these is a long, mysterious period of prehistoric humanity; further back still, our apelike ancestors; beyond them, more primitive mammals, then reptiles, then fish, then primitive vertebrates, then perhaps some sort of worm, right back to single cells, to microbes, and ultimately to the first living cells on Earth. Beyond these we go back into a chemical realm of molecules and crystals, and finally to atoms and subatomic particles. This is our evolutionary lineage.

In the course of our growing up and education, most modern people have implicitly or explicitly accepted both models of reality: a physical eternity and an evolutionary process. Within the sciences, both models coexisted peacefully until quite recently. They were kept safely apart. Evolution was kept down to earth, whereas the heavens were eternal. Evolution was the province of geology, biology and the social sciences. The celestial realm was the province of physics.

Charles Darwin and biologists who followed him had to try to fit the evolutionary tree of life into a mechanical universe that was not evolving – it was devolving. The world machine had no ultimate purpose, and no such things as purposes could be admitted within it. From the mechanistic point of view, living organisms are complex machines, inanimate and purposeless. The Darwinian doctrine is that the evolution of living organisms in no sense involves a process of purposive striving, nor is it divinely designed or guided; rather, organisms vary by chance, their offspring tend to inherit their variations, and through the blind workings of natural selection, the various forms of life evolve with no design or purpose, either conscious or unconscious. Eyes and wings, mango trees and weaver birds, ant and termite colonies, the echolocation system of bats, and all other aspects of life have come into being through the operation of inanimate forces, through blind chance and by the power of natural selection.

The Darwinian theory of evolution has always been controversial, and remains so today. Some people still deny that evolution has happened at all; others dispute that it is purposeless and depends on blind chance; and some go much further than Darwinism: they see the evolution of life on Earth as part of a universal evolutionary process.

Philosophies of universal evolution, such as the theories of progress so popular in Victorian England, conflicted with the universe according to physics. So did evolutionary visions such as that of Teilhard de Chardin,5 who saw the evolutionary process being drawn towards an end or goal, an inconceivable state of final unity. From the point of view of mechanistic science, such philosophies and visions have generally been regarded as illusory: the evolution of life on Earth is not part of a cosmic evolutionary process that is leading somewhere; it is a local fluctuation within a mechanistic universe that has no purpose at all.

We are all familiar with this point of view, which had a deep and pervasive influence on twentieth-century thought. This is how the philosopher Bertrand Russell expressed it in the context of the devolving world machine:

That man is the product of causes which had no prevision of the end they were achieving; that his origin, his growth, his hopes and fears, his loves and beliefs, are but the outcome of accidental collisions of atoms; that no fire, no heroism, no intensity of thought and feeling, can preserve an individual life beyond the grave; that all the labours of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system; and that the whole temple of Man’s achievement must inevitably be buried beneath the debris of a universe in ruins – all these things, if not quite beyond dispute, are yet so nearly certain, that no philosophy which rejects them can hope to stand. Only within the scaffolding of these truths, only on the firm foundation of unyielding despair, can the soul’s habitation henceforth be built.6

This cheerless prospect has indeed seemed inevitable to many modern people, and the replacement of the devolving world machine with an Einsteinian static universe made little difference to this pessimistic outlook. The mechanistic theory is more than just a scientific theory: it has been taken to be a dreadful truth that no rational person can deny, whatever existential anguish it may cause. In this austere faith the molecular biologist Jacques Monod proclaimed:

Man must at last wake out of his millenary dream and discover his total solitude, his fundamental isolation. He must realize that, like a gypsy, he lives on the boundary of an alien world; a world that is deaf to his music, and as indifferent to his hopes as it is to his sufferings and his crimes.7

But scientific theories are subject to change, and in the 1960s the theoretical universe of physics broke out of its eternity. It no longer looks like an eternal machine, but more like a developing organism. Everything is evolutionary. The evolution of life on Earth and the development of humanity are no longer a local fluctuation in an eternal physical reality; they are aspects of a cosmic evolutionary process. A variety of philosophers and visionaries have been saying this for years, but now this is orthodox physics as well.8

The evolutionary universe

Most cosmologists now believe that the universe began in a primordial explosion some 14 billion years ago and that it has been growing ever since. There are two possible futures. Either the universe will expand forever; or its expansion will slow down, stop, and begin to contract, ultimately resulting in a reversal of the Big Bang in a terminal implosion called the Big Crunch. Fashions change fast in cosmology, and the shifting theories depend on the estimated amounts of dark matter and dark energy that the universe contains. The nature of both is literally obscure. Dark matter contributes to the gravitational pull that slows down the universal expansion, while dark energy pushes the universe apart, increasing its rate of expansion. In 2010, the best estimate was that regular matter made up less than 5 per cent of the universe, with dark matter accounting for 23 per cent and dark energy 72 per cent. Most physicists seem to favour continued expansion; but some prefer the Big Crunch, and see in it a way to return to a repetitive eternity: for the Big Crunch could be the Big Bang of the next universe, and so on forever.

However, even if we assume for the purpose of argument that our universe is one in an endless series, we could never know whether they all develop in exactly the same way or evolve differently each time. All we can know about is the evolution of the universe we live in.

Opinions differ as to what happened in the first 10–30 seconds, but according to the ‘inflationary’ model, the universe had a very brief period of extraordinarily rapid expansion during which all the matter and energy in the universe were created from virtually nothing.9 After this, the inflationary model coincides with what is now called the ‘standard’ Big Bang model.

About a hundredth of a second after the beginning, when the universe had cooled to 100 billion degrees, it consisted of an undifferentiated soup of matter and radiation. Within three minutes, the neutrons and protons began to combine into helium nuclei. Within 30 minutes, most of them were combined in this way, or remained as free protons, hydrogen nuclei.10

After a further 700,000 years of expansion and cooling, the temperature dropped low enough that electrons and nuclei could form stable atoms. The lack of free electrons then made the universe transparent to radiation, and the ‘decoupling’ of matter and radiation allowed galaxies and stars to begin to form.

The evolution of matter continued within the stars, where nuclear reactions produced the many chemical elements that are found in dust clouds between the stars, in comets, meteors and planets. Such elements are thought to be formed with particular intensity when stars explode as supernovae. In the cold conditions of interstellar space the formation of molecules becomes possible; and in cool aggregates of matter, for instance planets, a great variety of crystals come into being, such as those that make up the rocks of the Earth.

In this sequence, the one, the primordial ‘singularity’, becomes many, as ever more complex forms differentiate within the universe as it grows.

This image is far removed from the constant mechanical universe of classical physics. The evolutionary conception is now being extended to everything, even to the fundamental particles and fields of physics. Here is a description by Paul Davies, a theoretical physicist:

In the beginning the universe was a featureless ferment of quantum energy, a state of exceptionally high symmetry. Indeed, the initial state of the universe could well have been the simplest possible. It was only as the universe rapidly expanded and cooled that the familiar structures in the world ‘froze out’ of the primeval furnace. One by one the four fundamental forces separated out from the superforce. Step by step the particles which go to build all the matter in the world acquired their present identities … One might say that the highly ordered and intricate cosmos we see today ‘congealed’ from the structureless uniformity of the big bang. All the fundamental structure around us is a relic or fossil from that initial phase. The more primitive the object, the earlier the epoch at which it was forged in the primeval furnace.11

The universe would have developed very differently if the laws and constants of physics had been even slightly different. There is no a priori reason known to physics why they should be as they are. Yet they are as they are, and so life on Earth and we ourselves have been able to evolve. The laws of physics have to take into account the fact that physicists exist. This consideration is essential to modern cosmology, and is expressed in the Anthropic Cosmological Principle. The ‘weak form’ of this principle is now widely accepted:12 ‘The observed values of all physical and cosmological quantities are not equally probable, but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirement that the Universe be old enough for it to have already done so.’13

Some physicists go further in advocating a ‘strong form’ of the anthropic principle: ‘The Universe must have those properties which allow life to develop within it at some stage in its history.’14

At first sight this seems tautological, a rather ponderous restatement of an obvious truth. Nevertheless it is intensely controversial because of its implication that the universe may, after all, have a grand purpose and design. Some cosmologists go even further:

Suppose that for some unknown reason the Strong Anthropic Principle is true and that intelligent life must come into existence at some stage in the Universe’s history. But if it dies out at our stage of development, long before it has had any measurable non-quantum influence on the Universe in the large, it is hard to see why it must have come into existence in the first place. This motivates the following generalization of the Strong Anthropic Principle: Final Anthropic Principle: Intelligent information-processing must come into existence in the Universe, and, once it comes into existence, it will never die out.15

For atheists and materialists, the idea of a universe designed in such a way that life and intelligence are likely to emerge has disturbing theological implications. But there is an easy way out, which has become increasingly popular since the turn of the millennium: the multiverse theory. Our universe could be just one of a vast number, perhaps even an infinity, of parallel universes, each with different laws and constants. Then there would be no problem about our universe being fine-tuned in exactly the right way for us to emerge within it, because we just happen to be in the right one for us. As the cosmologist Bernard Carr has expressed it: ‘Since we necessarily reside in one of the life-conducive universes, the multiverse picture reduces the strong anthropic principle to an aspect of the weak one. For this reason, many physicists would regard the multiverse proposal as providing the most natural explanation of the anthropic fine tunings.’16 In order to get rid of a God who fine-tuned the universe when it first came into being, many scientists are prepared to accept the existence of an infinity of parallel universes, for which there is no empirical evidence whatsoever. Some try to justify this move in terms of Occam’s razor, the principle of parsimonious explanation proposed by William of Occam, a fourteenth-century Franciscan friar: ‘Plurality should not be posited without necessity,’ or ‘Entities should not be multiplied beyond necessity.’

Multiplying entire universes without limit seems like the ultimate violation of Occam’s razor. But even this extravagant speculation cannot settle the matter:

Since within the world’s theistic traditions, God is considered infinite and infinitely creative, it makes sense that creation would reflect these attributes, and hence that physical reality might be much larger than one universe. Further it makes sense that an infinitely creative God might create these universes via some sort of universe-generator, since arguably this would be more elegant and ingenious than just creating them ex nihilo [out of nothing].

Robin Collins17

The very existence of such debates among contemporary physicists and philosophers shows how far modern cosmology has moved beyond the double worldview that has been orthodox for so many years. For generations of scientists, physical eternity seemed to be the basis of all reality. But this was not an absolute scientific truth, even though it was often regarded as such; it was just a theory – a theory that has now been superseded by physics itself. Whether the cosmic evolutionary process results from divine creativity or not, whether it has any purpose or not, and whether there are innumerable universes or not, according to the new cosmology, we live within an evolving universe.

Do the laws of nature evolve?

These evidence-free discussions about a universe fine-tuned by God, or a multiverse without a God, or a God of the multiverse, all share a common assumption: that the laws and constants of nature were all fixed from the outset. But as Terence McKenna remarked: ‘Modern science is based on the principle: “Give us one free miracle and we’ll explain the rest.” The one free miracle is the appearance of all the mass and energy in the universe and all the laws that govern it from nothing in a single instant.’18

The standard assumption is that physical reality evolves while the laws of nature stay the same. But why should we assume that all the laws of nature were already present at the instant of the Big Bang, like a cosmic Napoleonic code? The pre-existence of these laws cannot possibly be tested before the emergence of the phenomena they govern. In an evolutionary universe, perhaps the laws of nature evolve along with nature.

In any case, what do we mean by the ‘laws of nature’?

Water boils in the same way in Scotland, Thailand and New Guinea, and everywhere else too. Under given conditions it boils at predictable temperatures – 100°C at standard atmospheric pressure. Sugar crystals form in much the same way under similar conditions all over the world. Chick embryos develop in much the same way everywhere when fertilized hens’ eggs are incubated under appropriate conditions. We usually assume that all these things happen because the appropriate materials, given the appropriate physical and chemical conditions, are under the influence of natural laws – laws that are invisible and intangible, but are nevertheless present everywhere and always. There is order in nature; and the order depends on law.

These hypothetical laws of nature are somehow independent of the things they govern. For example, the laws governing the formation of sugar crystals do not operate only inside and around the growing crystals, but also exist outside them. They have an existence that transcends particular times and places. Thus the sugar crystals that are forming today in sugar factories in Cuba are not following local Cuban laws, but rather laws of nature which apply everywhere on Earth, and indeed everywhere in the universe. These laws of nature cannot be altered by any laws the government of Cuba may pass, and they are not affected by what people think – not even by what scientists think. Sugar crystals formed perfectly well (as far as we know) before the structure of sugar molecules was worked out by organic chemists and before the structure of their crystals was worked out by crystallographers; indeed these crystals were forming perfectly well before were any scientists at all. The laws have an objective existence quite independent of human beings, and even independent of the existence of the crystals themselves. They are eternal. They existed before the first sugar molecules arose anywhere in the universe. They have existed since the Big Bang, and they may have existed before there was a universe at all, as eternal realities which transcend time and space.

But wait a minute. How could we possibly know that the laws of nature existed before the universe came into being? Or that they all appeared at the instant of the Big Bang? We could not ever hope to prove it by experiment. This is surely no more than a metaphysical assumption. Nevertheless, this assumption is still taken for granted by most scientists, including evolutionary cosmologists. This assumption became habitual when physical reality was thought to be eternal, and has persisted in spite of the revolution in cosmology. But then where or what were the laws of nature before the Big Bang?

The nothingness ‘before’ the creation of the universe is the most complete void that we can imagine – no space, time or matter existed. It is a world without place, without duration or eternity, without number – it is what mathematicians call ‘the empty set’. Yet this unthinkable void converts itself into a plenum of existence – a necessary consequence of physical laws. Where are these laws written into that void? What ‘tells’ the void that it is pregnant with a possible universe? It would seem that even the void is subject to law, a logic that exists prior to time and space.19

This assumption that the laws of nature are eternal is the last great surviving legacy of the old cosmology. We are rarely even conscious of making it. But when we do bring this assumption into awareness, we can see that it is only one of several possibilities. Perhaps all the laws of nature came into being at the very moment of the Big Bang. Or perhaps they arose in stages, and then, having arisen, persisted changelessly thereafter. For example, the laws governing the crystallization of sugar may have come into being when sugar molecules first crystallized somewhere in the universe; they may have been universal and changeless ever since. Or perhaps the laws of nature evolved along with nature herself. Perhaps they are still evolving. Or perhaps they are not laws at all, but more like habits. Maybe the very idea of ‘laws’ is inappropriate.

The concept of laws of nature is metaphorical. It is based on an analogy with human laws, which are binding rules of conduct prescribed by authority and extending throughout the realm of the sovereign power. In the seventeenth century, the metaphor was quite explicit: the laws of nature were framed by God, the lord of the universe. His laws were immutable; his writ ran everywhere and always. Through his omnipotence, God was also the universal law enforcement agency.

Although many people no longer believe in such a God, his changeless laws have survived him to this day. But when we pause to consider the nature of these laws, they rapidly become mysterious. They govern matter and motion, but they are not themselves material nor do they move. They cannot be seen or weighed or touched; they lie beyond the realm of sense experience. They are potentially present everywhere and always. They have no physical source or origin. Indeed, even in the absence of God, they still share many of his traditional attributes. They are omnipresent, immutable, universal and self-subsistent. Nothing can be hidden from them, nor lie beyond their power.

Eternal laws made sense when they were ideas within the mind of God, as they were for the founding fathers of modern science. They still seemed to make sense when they governed an eternal universe from which God’s mind had been dissolved. But do they any longer make sense in the context of the Big Bang and an evolving universe?

When we look again at the source of the legal metaphor, human legal systems, we see at once that real laws do indeed develop and evolve. In the English tradition, the common law that governs so much of our lives has grown up over many centuries, rooted in ancestral customs and judicial precedents, continually developing as circumstances change and as new situations arise. And in all countries, new laws are enacted and old ones modified or repealed by the powers that be. Constitutional governments are themselves subject to legal constitutions, which likewise change and evolve. From time to time, old constitutions are overturned by revolutions and replaced by new ones, drawn up by constitution-makers. We apply this idea to science itself in the metaphor of scientific revolutions. They establish new scientific constitutions, within which new scientific laws are framed.

If we are to persist with the legal metaphor, it might be appropriate to suppose that the evolving natural world is governed by a system of natural common law, rather than by a preformed legal system established at the outset.

But then who or what corresponds to the judicial system that establishes the precedents? And who or what framed the constitution of the Big Bang in the first place? And by what power or authority are they maintained? These questions arise inevitably, because they are implicit in the metaphor of law. Laws imply lawgivers, and they are maintained by the power of the government. If we drop the idea that the laws of nature are framed and maintained by God, then we must ask: what makes them up and how are they sustained?

Many philosophers would deny that these questions have any meaning. From the point of view of the empiricist tradition, what we call the laws of nature are in fact human concepts that merely refer to regularities which scientists observe, describe and model. They have no real, objective existence. They are theories and hypotheses in human minds.20 So there is no point in asking how they arose as objective realities or by what power they are maintained.

But then what about the observable regularities to which these laws refer? What is the basis of the regularities of nature? They cannot depend on natural laws if these laws are only in human minds. And there is no basis for assuming that these regularities are eternal. The regularities within an evolving universe evolve: this is what evolution means.

The growth of habits

If the evolving regularities of nature are not governed by transcendent laws, then could they be more like habits? Habits develop over time; they depend on what has happened before and on how often it has happened. They are not all given in advance by eternal laws. Habits develop within nature; they are not imposed on the world ready-made. Sugar crystals, for example, form in the way they do now because countless sugar crystals have formed that way before.

This book explores the possibility that the regularities of nature are indeed more like habits than products of eternal laws. This exploration takes place in the context of a specific, scientifically testable hypothesis, the hypothesis of formative causation. This hypothesis is described in Chapter 6 and subsequent chapters. But the general idea that nature is habitual is by no means new: it has been tried out before, and was widely discussed towards the end of the nineteenth century and at the beginning of the twentieth. But the wave of interest in this idea ebbed after the First World War. It went out of fashion and sank into obscurity. Why?

The idea of the habits of nature was conceived of in an evolutionary spirit. For example, in the late nineteenth century the American philosopher C.S. Peirce pointed out that the idea of fixed and changeless laws imposed upon the universe from the start is inconsistent with a thoroughgoing evolutionary philosophy. Rather, the ‘laws of nature’ are more like habits. The tendency to form habits grows spontaneously: ‘Its first germs arose from pure chance. There were slight tendencies to obey rules that had been followed, and these tendencies were rules which were more and more obeyed by their own action.’21 Peirce considered that ‘the law of habit is the law of mind’ and concluded that the growing cosmos is alive: ‘Matter is merely mind deadened by the development of habit to the point where the breaking up of these habits is very difficult.’22

The German philosopher Friedrich Nietzsche, writing around the same time, went so far as to suggest that the ‘laws of nature’ not only evolved, but underwent some sort of natural selection:

At the beginning of things we may have to assume, as the most general form of existence, a world which was not yet mechanical, which was outside all mechanical laws, although having access to them. Thus the origin of the mechanical world would be a lawless game which would ultimately acquire such consistency as the organic laws seem to have now … All our mechanical laws would not be eternal, but evolved, and would have survived innumerable alternative mechanical laws.23

And somewhat later William James wrote in a vein similar to Peirce:

If … one takes the theory of evolution radically, one ought to apply it not only to the rock-strata, the animals and plants, but to the stars, to the chemical elements, and to the laws of nature. There must have been a far-off antiquity, one is then tempted to suppose, when things were really chaotic. Little by little, out of all the haphazard possibilities of that time, a few connected things and habits arose, and the rudiments of regular performance began.24

Other philosophers advocated similar ideas,25 but then this entire line of thought fizzled out. Physicists held firm to the idea of an eternal universe governed by eternal laws; and indeed this idea gained a new lease of life through Einstein’s general theory of relativity. Einstein postulated not a relative but an absolute, eternal universe. Events within this universe were relative to each other; but the background reality was changeless. We should remind ourselves again that it was not until the 1960s that an evolutionary cosmology became predominant in physics.

The idea of habit was also explored in the realm of biology. Living organisms seem to have within themselves a kind of memory. Embryos develop in ways that repeat the development of their ancestors. Animals have instincts that seem to embody ancestral experience. And all animals can learn; they build up habits of their own. All this was pointed out with admirable clarity by the Victorian novelist Samuel Butler. Memory, he concluded in Life and Habit (1878), is the fundamental characteristic of life: ‘Life is that property of matter whereby it can remember – matter which can remember is living. Matter which cannot remember is dead.’ Two years later, in Unconscious Memory, he went even further: ‘I can conceive of no matter which is not able to remember a little, and which is not living in respect of what it can remember. I do not see how action of any kind is conceivable without the supposition that every atom retains a memory of certain antecedents.’26

As embryos develop they pass through stages that recall the embryonic forms of remote ancestral types; in some way the development of an individual organism seems to be related to the entire evolutionary process that gave rise to it. Human embryos, for example, pass through a fishlike stage with gill slits. Butler saw in this a manifestation of the organism’s memory of its own past history: ‘The small, structureless, impregnate ovum from which we have each of us sprung, has a potential recollection of all that has happened to each one of its ancestors.’27

Such ideas were widely discussed by biologists until about the 1920s,28 and the theory that ‘heredity is a form of unconscious organic memory’29 was worked out in considerable detail.30 But by then the development of genetics seemed to have shown that heredity could be explained in terms of genes, made up of complex molecules, now known to consist of DNA. The memory of which Butler and others spoke appeared to be embodied in inanimate matter after all, and to be produced mechanistically. The notion of inherited habits of form and behaviour dropped out of biology.

However, as we will see in Chapters 4 to 8, in spite of all the successes of genetics, molecular biology, and neurophysiology, biologists have still not managed to explain the development of embryos or the inheritance of instincts in mechanistic terms. Chemical genes and the synthesis of specific proteins certainly have something to do with it; but how does the inheritance of a certain set of chemical genes and the synthesis of particular proteins make swallows, for example, migrate from a certain part of England to southern Africa before the English winter begins, and then make the birds migrate back to the same place in England in the spring? No one knows. No one knows how embryos progressively take up their forms or how instincts are inherited or how habits develop or how memories work. And the nature of minds is obscure.

In short, all these aspects of life are still mysterious. Many biologists believe that in due course they will cease to be so because they will all be explained mechanistically. That is to say, they will be interpreted in terms of physical and chemical models, and hence will ultimately be accounted for in terms of the properties of matter, fields and energy, governed by changeless laws of nature.

The idea of eternity that has inspired the theories of physics for many centuries remains a powerful force, and to understand why we have to consider its history. We do so in the next chapter; and then in Chapter 3 we turn again to the evolutionary vision of reality, a vision which is still growing and extending its scope, and which is proving to be more powerful than the vision of physical eternity – even in the heart of theoretical physics.