The Pleasure Principle

The ancient Epicureans were not impressed by the argument that integration and harmony always imply a mastermind creator or a team working closely together with oversight of the whole process of manufacture. But as watches and automobile factories were in their time unknown, no one was around to present to them the argument that such complex and well-functioning things can’t make themselves or appear by chance. If they had been confronted with such arguments, they might have insisted that a watch or a factory could arise through the chance combination of atoms. But I suspect they would have had to agree that it is probably impossible for a watch or a factory to assemble by chance. For this to happen, the various components would have to stick together and start to interact in just the right way. And to imagine a fly or a mouse or an elephant coming to be in this way strains credulity too far. Isn’t this like expecting (as 20th-century critics of evolutionary theory used to argue) monkeys with typewriters to produce the plays of Shakespeare?

This was a stumbling block that seemed to give the advantage to Creationism.

I can well understand that a person brought up on the Genesis story of the creation of the universe in seven days and sitting in the classroom listening to a lecture on how Darwin discovered the theory of evolution by natural selection would be sceptical about his supposed achievement. Such a person might reasonably wonder: how could just one scientist in the 19th century looking at finch beaks in the Galapagos, and talking to pigeon breeders in England, prove that we evolved over hundreds of millions of years from apes and monkeys, which in turn evolved from something like fish and worms?

Even if you favour the Darwinian view over the Genesis story, it is good to remember that, on the face of it, it is somewhat implausible. But conversely, if you find Darwinism implausible, it is helpful to stop thinking of Darwin as suddenly and single-handedly coming up with a new and startling theory for which there is still no conclusive evidence. You can think of him instead as one of a long line of thinkers familiar with Epicurean philosophy who found the way over its major stumbling blocks where the theory of natural selection was concerned.

Darwin’s Upgrade: How Selection Causes Evolution

Lucretius’s claim that nature had experimented with unsuccessful animal species that lacked the right structure to maintain themselves and reproduce was well known to the 18th- and early-19th-century theorists with whom Darwin was familiar. (One of them was his own grandfather, Erasmus Darwin, the author of a long poem on the origins and evolution of life). The early, hostile reviews of On the Origin of Species all mentioned its relationship with the Lucretian text. One reviewer complained, for example, that there was nothing new in Darwin’s ‘speculative’ cosmogony. ‘It is at least as old,’ he said, ‘as Democritus and Epicurus, and has never been presented with more poetic beauty than by Lucretius.’

Darwin did not attach his own account to Epicureanism, and especially to Lucretius’s version, for obvious reasons. First, Lucretius (and grandfather Darwin) were notorious atheists, and Darwin kept or tried to keep his sceptical views on religion to himself. Second, he had to fend off the charge that his theory of evolution was a poetic fantasy or mere speculation. What, then, was he able to add to (and subtract from) the Epicurean theory that plants and animals evolved ‘by chance’ that changed its status in his mind and eventually in the minds of his early followers? How did Darwinism go beyond speculation to develop into an accepted account of the origin of the various species?

By the time the 19th century rolled around, most naturalists were doubtful that the astonishing number of different species then identified – far too many to have fitted on the Ark – including hundreds of different species of beetles, had been created by twos and on purpose. The true age of the earth had been calculated, and the former existence of the dinosaurs and the giant mammals that had once roamed Europe and Asia was generally known. Two scientific developments transformed the Epicurean theory of the natural origins of plants and animals from a somewhat implausible speculation to a well-founded scientific hypothesis. These were: the cell theory, and the notion of ‘variation’ from generation to generation.

The discovery, based on the microscope, unavailable to ancient philosophers, that all plants and animals were combinations of individual living cells, and that some cells were free-living animals like the amoeba, made it possible to think of the origins of life in terms of the first appearance of a living cell. To imagine, as Epicureanism required, an elephant emerging from a combination of atoms or even from an atomic seed in the earth was far more difficult than imagining a few single cells forming by chance and later joining up into larger cellular units.

Another obstacle for the Epicurean theory was the assumption that animals always gave birth to animals like themselves. This seemed obvious to them. Cows did not give birth to sheep, or blackbirds to swallows. This meant that they had to stick to their theory that the original prototypes of every sort of animal had sprung by chance from the earth. Although they fancied that not all of these animal types had been capable of survival and reproduction, they could not envision the descent of one kind of bird or mammal from an entirely different kind of bird or mammal.

Darwin’s breakthrough occurred when he reflected on the selective breeding farmers had carried on for millennia, choosing from the pack or flock or herd, and breeding together male and female dogs, sheep and cattle with desired characteristics. He knew that within the group, individuals varied in their qualities and that offspring were not exactly like their parents. To the idea of variation, he was able to apply the Epicurean idea of selection – success or failure in living and reproducing.

For Darwin, nature, acting unconsciously, rather than the breeder acting with intention, did the selecting when the resources needed for life were limited and predation was the rule. Animals ate and sometimes killed plants and killed and ate one another. Bacteria, fungi and poisonous plants killed animals. Plants derived nutrition from decomposing animals. Naturalists had long wondered why, if the world was created by a supremely benevolent and skilled craftsman, this was how things worked. They also wondered why trees produced so many useless seeds and short-lived seedlings; why humans produced such an oversupply of ‘spermatic animals’; and why so many children died in infancy. The grim truth was that competition for life was intense. Many individuals of a given species would starve, be eaten or die of accidents before reproducing, or fail to find or attract mates. Darwin argued that the appearance of entirely new species was the result of thousands or millions of generations of variation and selection in changing environments. The temporary stability that the Epicureans had ascribed to the world, which they saw as constantly evolving as the atoms fell into new combinations, was a feature of the individual species as well, and the mortality of the individual person applied to the whole species, whose eventual extinction was similarly inevitable.

Darwin’s contribution, to my mind, was not just to think out how natural selection might work, but to show that it could be considered a lawful process rather than one based entirely on chance. For the constantly repeated accusation against the ancient Epicureans was that the beauty, intricacy and functionality of the many forms of life could not arise from the random motions of atoms. But, in Darwin’s view, the breeder who seeks to improve his or her flock of sheep or hunting dogs, or the pigeon fancier who presents his or her fluffy tailed or brightly feathered specimens to other fanciers, is employing a technology, and wherever a technology is successful, there we expect to find laws of nature. Nature, too, must be employing a technology to create the succession of living forms of the past near 4 billion years.

To be sure, nature is not aiming to improve any individual species or the livestock or biomass of the planet itself. She is not trying to make animals or entire species faster, smarter or more beautiful. In fact, nature is not trying to do anything. But she mercilessly eliminates some members of each species who aren’t keeping up with the others in producing, and in some cases raising to maturity, offspring who will have their own offspring. As a result, the face of living nature changes in ways we can often explain. Species have appeared and disappeared over the eons, and for this to have happened, there must be laws of nature underlying these changes. Chance – or what we think of as chance, namely coincidence – nevertheless plays a role. Many organisms perish, not because they lack strength, speed, cunning or good metabolisms, but just because they were in the wrong place at the wrong time. A good example is the class of dinosaurs that just happened to be inhabiting the earth 65 million years ago when it was hit ‘by chance’ – though fully in accord with the laws of physics – by an asteroid that wiped them all out.

The Lucretian account of the formation of the cosmos and the evolution of animals, and the Judaeo-Christian account of the divine creation of the world, were recognised as rivals from the early medieval period onwards. Their combat has been long and persistent, but also somewhat hidden from view, which is why Darwin receives too much credit for thinking out the basic idea of evolution by natural selection and too little credit for realising that variation was the key that could solve the problem of the origin of new species. The rivalry was not for a long time manifested in open debate because of the severe criminal penalties attached to blasphemy, a capital crime in earlier periods of Judaism, Christianity and Islam, and because of the ubiquity of censorship in many parts of Europe.

Why were ideas about the origins of life so dangerous? It was thought that if too many people began to take seriously accounts of the natural origins of life, they would cease to believe that they were created by and responsible to the God who had created them. If they stopped believing they were responsible to God, they would stop believing that obedience to God’s commands and their rulers was obligatory and that disobedience would be harshly punished. If they stopped believing that obedience was obligatory, they would become libertines, criminals and revolutionaries.

Today, the fear that motivated execution for heretics and resulted in the banning, confiscation and burning of scientific books takes a different form. It is not fear of revolutionary violence that explains the persistence of Creationism and intelligent design theories. Some Creationists would probably like to overthrow their secular governments by force of arms and replace them with theocracies. The fear is rather that if the Epicurean–Darwinian theory is true and intelligent design false, divinities and religious texts are not sources of moral authority, and eternal life is not the reward for faith. In that case, there is no reason to obey the Ten Commandments or all the moral ordinances of one’s own church. Moral anarchy, by which Creationists usually understand homosexuality, adultery, abortion and divorce, and the breakdown of the family and society, will result.

If the divine-command theory of morality were the only option, and if the inescapability of death actually spoiled our lives, worries about the social and psychological effects of accepting evolutionary theory might be justified. But it was Darwin himself, drawing on a long tradition of secular British moral theory as well as his own observations of birds and mammals, who first argued that certain forms of altruism characterised group living animals, contributing to their survival. Conscience, or a moral sense, would inevitably arise, he declared, in any social animal that had developed intelligence comparable to that of a human being.

More recent research on primates and young children has confirmed that the moral sentiment of empathy and the disposition to help others, along with a preference for fairness, are to some extent prefigured in our evolutionary ancestors and wired into us from birth. These endowments can be strengthened and extended, as Darwin saw, through formal learning, or weakened by experience and indoctrination. And despite having no conception whatsoever of the descent of one species from an entirely different one, the ancient Epicureans had a serviceable theory of natural morality that I’ll explore in Chapter 6. They showed how it was possible to live cheerfully and ethically as a mortal.

3

The Material Mind

The spirit … is born with the body, develops with it, and succumbs with it to the stress and strain of age.

Lucretius

Even if you are not tempted by Creationism, you may well wonder how conscious awareness and the power of perception and thought – mind or spirit – could arise from combinations of material particles. In keeping with their sparse ontology of atoms and void, the ancient Epicureans declared the soul – the principle of movement, sensation, experience and thought in living beings – to be composed of a special sort of atom. ‘Soul atoms’, they proposed, were especially small, especially mobile and very lively. They pervaded the limbs of the human body, enabling us to think, feel and move. Unlike the soul of Christian and other theologies, the Epicurean soul was not immortal or an object of special care and concern by contrast with the body.

We feel and know that we are wholly united with our bodies, says Lucretius. ‘The spirit’s interpenetration of the body through veins, flesh, sinews and bones is so complete that even the teeth are given a share in sensation, as is shown by toothache, or the twinge caused by icy water, or the crunching of rough grit concealed in a piece of bread.’ Too much wine has the effect of ‘confounding the spirit within the body’. Now, ‘the limbs become heavy; [the drunkards] reel about with staggering steps; the tongue drawls, the mind is sodden, the eyes swim’. In an epileptic fit ‘the spirit in every part of their frame is so distracted by the violence of the seizure that it surges and foams, just as the waves of the salt sea seethe beneath the furious force of the winds’.

Because body and mind are entirely interwoven, the body cannot live on and experience sensation without its mind, and the mind divorced from the body cannot produce any thought or movement. At the moment of death, the soul particles escape into the surrounding atmosphere without causing any immediate change in the weight or shape of the body. ‘It is like the case of a wine whose bouquet has evaporated, or of a perfume whose exquisite scent has dispersed into the air, or of some object whose flavour has departed.’ The death of the body most certainly means the permanent annihilation of that body’s mind.

The Mystery of Consciousness

The 17th-century philosopher René Descartes, who had no problem with the Epicurean account of the origins of plants and nonhuman animals, famously balked at taking the same view of humans. Where plants and animals are just unconscious material machines, human beings, he argued, are material machines that also possess an incorporeal, immortal soul that endows them with conscious awareness, free will and rationality. Each human soul must have a divine origin. Not only did this claim excuse him from having to try to explain consciousness, free will and rationality in mechanical terms, it enabled the rest of his basically Epicurean ‘corpuscularian’ philosophy to make it past some of, though not all, the censors. (Despite his extensive references to God and the incorporeal soul, his books were viewed with considerable suspicion and for a time appeared on the Index of Prohibited Books of the Catholic Church.)

Descartes’s official theory of the special human soul put him in good and extensive company. The majority of the human race believed in his time, and the majority still believes, that the soul is a something that lives in the body. The soul is thought of as a permanent, indestructible entity that can survive the death of the body. Not only can it survive, it can reattach itself to a new living body – either the resurrected body of the person who died, or one of their descendants, or an animal of another species – where it will continue to see, feel and think to the extent permitted by that body. The Epicurean of today will, however, insist that the soul is not able to detach itself from its original body or attach itself to another unensouled human body. My death, she supposes, will be the end of all my experience and thinking, and it will not be the start of some other being’s experience and thinking, except in the sense that some of the particles composing me may eventually find their way into another organism.

But if we don’t have immaterial and potentially immortal souls or minds, how can thought, experience and voluntary movement be explained? No one today can take seriously the idea of soul atoms. As we see it, there is something about how my living body is put together from individually lifeless and thoughtless particles that enables me to be conscious, aware of my environment, subject to pain, able to initiate actions, to reflect on myself and the world, to make plans and decisions, and to build and create. Nothing more than a brain, composed of molecules, which are composed of atoms, which are composed of subatomic particles, located in an animal body is needed for experience, thought and voluntary movement. And it is not a foregone conclusion that a brain is necessary for feeling and deciding. Other biological structures found in living beings, or even other structures or programs that could be placed into computers, might make thought and feeling possible.

The Evolution of Consciousness

It is currently thought that consciousness may be widely distributed in nature. There is little doubt that mammals and birds have experiences and feel emotions, and the sensation of pain must have appeared very early in evolutionary history. As difficult as it is to imagine the experiences of a gecko or a spider, many animals, including fish, reptiles, cephalopods like octopi and squid, and even insects, have a good claim to awareness of a sensory world of flavours, odours, sounds and visible, tangible objects and substances.

Still, it might seem incredible that consciousness and all our mental powers, including rational decision-making and creativity as well as perception and feeling, could arise from purely physical underpinnings, from processes in our brains that work according to the laws of physics and chemistry. The alphabet analogy goes some way towards explaining how individual elements – letters – can give rise to composites – words and sentences – with new qualities. But we may still wonder how, from the ultimately real colourless, odourless, tasteless, silent particles and forces, consciousness can present to us a world of flavour, colour, scent and sound.

No one has ever explained, scientifically, how we can be aware of a world and why we experience the qualities we do – why the scent of roses is as it is, and why certain wavelengths of light are correlated with the experience of red rather than the experience of blue. No one has ever explained how I can initiate an action voluntarily and deliberately. Nevertheless, the Epicurean of today asks: which is more likely? That whether we can ever explain it or not, consciousness and mentality arise from purely physical underpinnings, nothing more being required? Or that a non-physical entity lives in us somewhere and, when connected properly to a functioning physical brain, enables the possessor of that brain to think, feel, perceive and decide?

A more tractable question than ‘How does conscious awareness arise?’ is the question of why conscious awareness is useful. Developing lungs or wings enabled prehistoric animals to exploit particular features of their environment: to move from the sea onto the land where there were new things to eat, or from land into the air, where many predators could be avoided. But what does having awareness, consciousness of a world and, with it, knowledge of how my body is related to other bodies enable me to accomplish what I couldn’t accomplish if I were a well-programmed unconscious machine? With robotics constantly improving and developing remarkable recognition and navigation skills, this question is highly actual.

To see why, despite technological advances, consciousness might be necessary for many living things, consider the simple robot known as the Roomba. The Roomba is a disk, about 16 inches in diameter, with two independently operating wheels, that gets plugged into the wall to charge. It then runs around your floor sweeping up crumbs and dust. According to its literature, it is able to ‘change direction upon encountering obstacles, to detect dirty spots on the floor and to sense steep drops to keep it from falling down stairs’.

The Roomba does only one thing, but it does it reasonably well: it forages for dust and dirt. Successive generations of Roombas evolve, because consumers want and will pay for upgraded models with fewer problems and more capabilities. It is, however, not a machine that transforms raw materials into energy and work. It does not use the dust and dirt it collects to keep running. Because it can draw on an unlimited supply of electricity from the wall to recharge its batteries, it does not need to be self-sustaining. It is highly dependent on its owner for continuing operation, for it can get stuck under furniture and run out of charge.

Now imagine we want to build a robot that forages for food outdoors on variable terrain, rather than for dust and dirt on flat indoor surfaces, and that it will convert this food into the fuel that powers its movements. It now faces certain dangers, not only from sharp rocks and precipices in its environment, but also from heat, cold and rain that will destroy its electronic components. It must avoid consuming non-food substances. It must be efficient in expending its energy if it is to survive, because the amount of food it can find, consume and metabolise for power is limited. This robot is mortal. It can just wear out, like the Roomba, through friction and corrosion. But it can also ‘die’ if its energy needs exceed the amount of food it is able to find, consume and convert to power, or if it fails to detect a lethal danger. It may also be attacked and killed by another robot that can consume its body for fuel or replacement components, or by an irritated human being.

Using present technologies, this robot will have very complex software. It will need to perceive the difference between food and non-food that closely resembles food. It will need a memory to avoid wasting energy searching in places where no food was found recently, but some such places may become good sources of food in the future, and it will need to remember that. In order to know when to start foraging and when to stop, it will need sensors that monitor its energy needs. It will need a decision mechanism that can make critical choices, such as the choice to continue its food search even when its energy stores are so low that it may ‘die’, or to abandon the search to conserve energy and to wait for food to replenish itself in the environment.

Now let’s imagine that the robot can reproduce. It will build copies of itself that accidentally vary slightly. Either it must build full-size copies of itself or smaller variant copies that will grow as they consume nourishment. If the former, it will expend large amounts of energy; if the latter, new software will be needed to direct growth. A robot that exists among other robots competing for the same food and shelter and competing to be a faster producer of little robots will have to be endowed with better competencies than theirs. If it is a sexually reproducing robot, it will also need to be able to identify potential ‘mates’, and to perform courtship behaviour that is successful in inducing the other robot to cooperate.