Aristotle

 Aristotelians often speak with admiration of the Philosopher's prose. They commend his ability to compress so much meaning into so few words. But. in truth, the pleasure that they derive from unravelling his tortured syntax and recondite metaphors is the pleasure of tackling a cryptic crossword. He is often shockingly opaque. Were he not, classical philosophers wouldn't still be hacking at his texts more than two millennia after they were composed and fewer of them would have jobs. I have before me three monographs and one paper published within the last ten years. Each is by a gifted scholar and each analyses this one, metaphor-laden passage with an acuity, even brilliance, that I cannot hope to match. To varying degrees they all disagree about what it means. And I don’t quite agree with any of them. 

Rewritten into plainer English I think that the passage says this. “What makes the cosmos good = even the best possible? An army or a household has an organizing principle (the general master) and its members have an ordered set of relationships to each other. Does goodness depend on the organizing principle or on the ordered relationships? The answer is: on both, but mostly on the former since that dictates the latter. Like an army or a household, the organisms that inhabit the world are connected to each other by a set of ordered relationships. And, like them, that order is due to some organizing principle, not a man, but a common goal. [“For all things are jointly ordered with respect to one thing.”] But not everyone in an army or a household contributes equally to that common goal. Senior members (officers/masters higher animals) contribute more than junior members (troopers/slaves plants); that’s just their nature. Although all of the world’s creatures are necessarily individual entities (and so have their own goals), they also all contribute to the common goal.’ 

Aristotle’s household analogy is both beautiful and familiar. It appeared. albeit less explicitly, in his discussion of bodily economics, as the underpinning of what I called his ancillary teleological principles. Here he invokes it to explain the structure of the cosmos itself. But, of course, it is familiar for another reason. When, in 1866, Ernst Haeckel coined oekologie to describe the new science of the economics of nature, it was from oikos Greek for household that he did so. The coincidence is testament to the metaphor’s power. But it also makes us wonder: are all the different kinds of animals in the world truly like a household insofar as they are subject to some common organizing principle; or are they more like the residents of a hotel who just happen to find themselves under a single roof? On this question much of the history of modern ecology turns. It is a question that might be asked of Aristotle too. 

Aristotle’s claim that organisms are related to each other as members of an army or a household is, as I read it, a frank anomaly. It invokes a higher, inter-species level of organization, a common cosmic purpose or a global teleology. In the Politics Aristotle makes clear that a properly functioning household is not just an assemblage of self-interested individuals. Rather, it is a collective of co-operating members, directed by the household’s master, whose collective purpose is procreation and protection. Yet, when speaking of animals, he hardly ever describes the kind of co-operative, even altruistic, inter-specific behaviour that we might hope to find in an army or a household. True, he claims that the karidon (or pinnophylax), a little symbiotic shrimp or crab, benefits the pinna, the giant fan mussel, in which it lives, but he makes nothing of it. And when he explains some animal’s features in functional terms he almost invariably speaks of its benefit to that particular kind of animal. If all the species in the world share some organizing principle or common purpose beyond a desire for their individual survival, his zoology does not tell us what it is or how they accomplish it. Aristotle’s forms are selfish forms. 

Moreover, there is one kind of global teleology that he explicitly rejects. The strongest form of global teleology would be one that postulates that the world, perhaps even the whole cosmos, is a single super-organism. Such a world would be one over which Gaia reigns with a power far beyond James Lovelock’s wildest imaginings. It would be a world like James Cameron’s Pandora, one whose inhabitants are all connected by a vast signal transduction network, whose predators are not so much the ecological equivalent of jackals and hawks as phagocytes coursing through the planetary circulation, and whose animals rise as one in response to the planetary spirit’s anguished call to arms. Or, since we are not in the twentySecond century AD but in the fourth century BC, it would bea world like the One that Plato describes in The Timaeus. Plato’s perceptible cosmos is a copy of a single form, the Intelligible Living Creature. The name says it all. The cosmos has a ‘soul’. Designed by the Demiourgos it is also designed for the Démiourgos. Even our bowels are arranged so that we can think about Him, But Aristotle is clear: the cosmos does not have a soul. (Though, as will become apparent, the celestial realm is not devoid of life cither.) 

It is for these, and other, reasons that most recent interpreters of Metaphysics A. 10 have read the household analogy in a very weak sense. They argue that when Aristotle says that living things are ‘jointly ordered with respect to one thing’ he is just saying what he has so often said: that they all aspire to eternity And I would agrce but for three reasons. The first is that this reading renders the analogy otiose. Why even bother giving it? The second is that Aristotle does describe some altruistic species. Oddly, they include sharks. 

He is explaining why sharks (and dolphins) have the faces they do. They have narrow snouts and their mouths are slung under their heads. These features, he thinks, make them inefficient predators since they cannot open their mouths very wide and, while seizing their prey, have to turn belly up which lets the little fish escape. He explains these awkwardnesses in two ways. One is that it prevents sharks from gorging themselves. That's quite consistent with Aristotle’s usual style of explanation. He often argues that animals have built-in limits to the amount of food that they can eat, or the number of eggs that they can lay, or the quantities of semen that they can produce; and such limits, he invariably goes on to explain, are the consequence of some other feature that benefits the animal. They are, as we would say, functional trade-offs. It’s his other explanation that is startling, For he also says that sharks have narrow gapes and under-slung mouths so that they don’t devour all their prey (nature appears to do this for the sake of the preservation of other animals’). Shark faces, it seems, are designed for the sake not only of sharks but of sardines too." 

The story of the shark’s face is so strange that it’s tempting to dismiss it as an un-Aristotelian interpolation. That seems unlikely since it appears in both Historia animalium and The Parts of Animals. So defenders of individual teleology sometimes say that Aristotle is just relating a popular notion ~ the sort of thing a fisherman might say. Or else, more subtly, that a good-for-sardines face is just an incidental benefit of its true in refund form, hav. -for-sharks design. I am less sure. A shark face that helps sardines to live is just the sort of feature that we would expect if, as Metaphysics A, 10 say® the world were like a household. In fact 1 believe that this Passage solves a deep and hidden problem in Aristotle's ecology. 

That is my third reason for taking Aristotle’s household ananalogy seriously. Most scholars agree that Aristotle believes that: (i) organisms are designed to survive and reproduce; (ii) animal kinds are eternal. They have, however, failed to note that these two beliefs are, in general, incompatible. That is because, in a world in which organisms interact with each other, in which they compete and prey upon one another, there is no reason to suppose that all will persist for ever. Animals and plants often extirpate their competitors; predators eat up all of some prey species and then turn to eating something else. At least so it is in our world. In Aristotle’s world, however, extinction is not an option; his metaphysics demands a balance of nature. Aristotle, I propose, grasps that such a balance does not emerge automatically from any self-interested assemblage of organisms, but must be designed by nature. 

The evidence for thinking this is admittedly indirect. To begin with the evidence closest to the subject, he must have had if I am right some grasp of the fragility of ecological communities. In Historia animalium, speaking of fish, he says that if ‘all their eggs were preserved they'd be infinite in number’. He’s also impressed by the extraordinary fecundity of mice and speaks of how sometimes they multiply so rapidly that their predators cannot make a dent in their numbers, that they devastate entire crops, and that they then, suddenly, disappear again, but no one knows why.” His description suggests that he’s relating an unusual phenomenon. That is indeed so. In the Nicomachean Ethics, discussing ‘incontinent appetites’ in humans he’s pretty severe on them he asks whether animals can have them too. His genial reply is that since animals can’t reason we don’t generally speak of them as being ‘temperate’ or ‘self-indulgent’ except in a metaphorical way. Yet, he continues, some kinds of animals exceed others in ‘wantonness, destructiveness, and omnivorous greed’ ~ he’s surely thinking of those pernicious mice and that they are a departure from ‘whar’s natural, as, among men, madmen are’. 

Such passing comments certainly do not amount to an ecological theory. Yet they do tell us that he has a sense of the normal relationship of animal populations to their food and that, sometimes, this relationship goes awry More generally, introducing his soothsayer derived account of animal conflict in Historia animalium, he says: ‘A state of war cxists between animals Which occupy the same place and get their livelihood [zoe] from the same sources.” It is one of his few explicit ecological principles but it is a deep one.” He never says that animals might go extinct for want of food. On the other hand he sees that an adequate supply of food is not automatically guaranteed for any given specics and that, faced with limited resources, individuals and species compete. 

Passages that speak of ecological instability are, however, rare in Aristotle's works. He seems to believe that nature usually ensures that there’s enough food for everyone. In the Politics, discussing the various ways in which men and animals make a living, he says that: 

Nature seems to provide a basic livelihood to all when first born and when fully mature [italics mine]. Some animals (e.g. larva-bearing and egg-laying animals) bring forth alongside their offspring enough food to last until they can provide for themselves. For a limited period live-bearing animals have food for the young inside them called milk. We should similarly infer that after birth plants exist for the sake of animals and other animals for the sake of human beings, the tame for service and food, and most wild ones for food, clothing and other uses. If nature makes nothing without purpose or in vain she must have made all animals for the sake of human beings. 

Some have read this passage as implying that Aristotle's teleology is purely anthropocentric; that, like Xenophon before and the Stoics after, he sees the whole world, and all the animals in it, as existing just for the sake of man. He really can’t mean that since the rest of his teleology is, as I've said. overwhelmingly directed at the survival of individual animals. But at the very least this passage does point out that plants, anima and nen af connected to each other by a chain of trophic re “bent bah at the! depend on each other, and that this isn t wen acciden’ | ut " “he has arranged matters this way. There is, then, a sense in which more perfect creatures typically use less perfect creatures as instruments of their survival since they eat them. But whose nature is at work here? When Aristotle says that ‘nature’ does this or that, he nearly always means the formal or material nature of some particular animal. Here, however, nature appears to refer to a higher level of organization. It appears to be the nature of the cosmos itself to ensure an adequate supply of food for all the animals in it. 

The cosmos is a holon, a whole. As such it is like a soul, a houschold, a state or even a tragedy Aristotle applies the term to them all. By a ‘whole’ he means a complex object that is something more than the sum of its parts, a system. But Aristotle is acutely aware of the fragility of wholes. His theory of the nutritive soul is, ultimately, an account of the material flows and regulatory devices that keep animals alive; his account of death is an account of how they fail. Much of his political theory is about the conditions that ensure the stability of the state. It would be strange indeed if he did not see that what is true of these wholes is also true of the greatest, most complex whole that he knows: the cosmos itself. 

This, I believe, is the force of his houschold analogy. It is a statement that, if the components of the sublunary world ~ all its plants and animals forms are to survive for ever, then their relationships must be arranged just so. Sharks must control their appetites for if they did not sardines would go extinct, and if sardines went extinct that would be bad for sharks. In the Nicomachean Ethics he reinforces this. He’s speaking of the difference between true wisdom and mere political ability or ‘prudence’, by which he means the ability to manage a household or a state. He says that prudence for humans and prudence for fishes are quite different. That’s unarguable, but raises the question: how can a fish be prudent at all? None of his fishes are ‘political’ by any definition. I suggest that he means thata fish ashark is prudent as a man is, by managing its income, by eschewing unnatural gluttony, by preserving its oikos its home and so itself. He even suggests that they have foresight. Animals are indeed designed to promote their own interests, but not so much that they jeopardize the existence of other kinds, for that would jeopardize their own. 

The hierarchical dimension of the household analogy is very unclear, but I believe Aristotle to be claiming that humans and animals have more diverse ways to realize their goals than, say, plants whose only function is to reproduce. Whether or not this is so, his houschold clearly invokes a far weaker form of global teleology than Plato's cosmic super organism in which all interests are subordinate to those of the Demfourgos. It is more to appeal to another organizational analogy like the kind of mutual self-interest that exists among industrial corporations and the myriad companies that supply the components they need, all of which seek one thing ‘the most excellent thing there is’ in their case, profit.” This vision of a cosmic teleology has one further benefit. It suggests a solution albeit a frankly speculative one, for which there is no direct textual evidence to the mystery of why spontaneous generators exist. Aristotle would deny Macbeth’s dismal claim that a man’s life is mere sound and fury signifying nothing. Speaking as a biologist (rather than a political scientist), he would say that the reason that he is born, grows to maturity and battles the vicissitudes of the world is so that he can reproduce his form. Not so the oyster. Its life, by his account, really does seem to be devoid of purpose for it perpetuates nothing. But perhaps this view is too narrow. For the oyster, and all its fellow spontaneous generators, do have this in common: they are eaten by other things. Most of them are at the bottom of the food chain. Perhaps, then, the purpose of spontaneous generators is to ensure the survival of the creatures that feed on them. They exist, as all living things do, to keep their world intact. I should love Aristotle’s teleology to be entirely aimed at the survival of individuals. That would make him seem quite modern Darwinian, if not NeoDarwinian. But if the picture that I have given of Aristotle’s world is accurate, then it is a very different one from ours. In our world natural selection maximizes short-term reproductive success and is indifferent to eternity: ‘[Natural selection] does not plan for the future. It has no vision, no foresight, and no sight at all. If it can be said to play the role of watchmaker in nature, it is the blind watchmaker.” Just so. In our world, therefore, species drive each other extinct. Around ap 1280 the Maori brought the Polynesian rat to New Zealand. It ate up five species of native birds and three frogs as well as a variety of lizard, insect and land-snail species. The Maori themselves ate up nine species of Moa. Now imported European predators Norwegian rats, black rats, stoats, weasels and cats = are working their way through what is left of the native fauna. If in our world, there is a ‘balance of nature’, it is only the temporary truce of evenly matched opponents who, having battled in the theatre of ecological war, stand exhausted among the corpses of the less fortunate and well equipped. Aristotle’s world is not a kinder one, for in it there are no truces, just battles that go on, without respite, for ever. 

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Let’s accept, ex hypothes!, that the cosmos shows the signature of purposeful order, the hallmark of design. Where does it come from? There are three, and only three, possible answers. The first is to appeal, as Plato did and Christians still do, to a beneficent creator who arranged things just so. The second is to appeal, as Democritus did and Epicurus would, to an infinite universe infinity solving all low-probability dilemmas. The first can be discarded; the second I have no views on, though some cosmologists believe it to be true.* As a biologist, however, I like the third for it depends on the only known mechanism capable of creating order from disorder: natural selection. 

This is the reasoning behind Cosmological Selection Theory, which proposes the existence of a population of universes — a multiverse; that these universes reproduce, that they do so with unequal success, and that they transmit their physical constants, allowing for some mutation, to their progeny universes. It’s nothing more or less than cosmic Darwinism and an easy route to a universe which, depending on the fitness function, has any non-lethal combination of parameter values that you please. One multiverse theory holds that universes give birth to baby universes via black holes. In that case, the number of black holes in our universe (millions) would be a design feature. The plausibility of the physics need not detain us; but, granting them, or some similar scheme, it is clear that natural selection among universes will work. If it has, far from being the mere product of brute material necessity, some of the features of the universe would be as teleologically explicable as the parts of an elephant. 

Such a cosmos would have a purpose. In such a cosmos, Aristotle would surely be at home. And yet he would reject a selectionist explanation for its Origins, just as he would reject a creator and chance. Ask Aristotle, how did the cosmos come to have its purposeful features?, and he would say: that’s a meaningless question since the cosmos didn’t come to be. It just is and was and always will be, forever and forever and forever. Of all his theories this, I think, is the one that we most struggle to understand. 

WE ARE APPROACHING GOD. I have mentioned, in passing how Aristotle thinks that stars, humans and even bees are ‘divine’, but perhaps you took that merely as a fagon de parler, Aristotle’s way of describing beauty, high intelligence or a complicated social life. God has even cropped up once or twice by name, but perhaps you thought that He was just a metaphor for something like Plato’s absolute good. If so, that is doubtless my fault. I have kept Aristotle’s theos in the shadows. It may even be that I have done so deliberately; that I have been reluctant to reveal the degree to which my hero’s scientific system is riddled with religion. Yet it is. In truth, God has been with us all this time. 

Why does Aristotle think that the stars are alive? He certainly doesn’t give any evidence for it. In The Soul he says, ‘By life we mean the capacity for self-nourishment, growth and decay’ — but the stars, he also says, do nothing of the sort. They neither have nor need organs. True, he says that they have souls and that they’re enjoying themselves up there, but how does he know? It’s mere assertion. It’s a bizarre stance to take — at least it is fora scientist who’s so cautious about the reproductive habits of bees. He seems 

to be star-struck: 

The reasons why the first body [aither] is eternal and not subject to increase or diminution, but unageing and unalterable and unmodified, will be clear from what has been said to anyone who believes in our assumptions. Our theory seems to confirm experience and to be confirmed by it. For all men have some conception of the nature of the gods, and all who believe in the existence of gods at all, whether barbarian or Greek, agree in allotting the highest place to the deity [italics mine], surely because they suppose that immortal is linked with immortal and regard any other supposition as inconceivable. 

Which shows that he’s God-struck too. 

There is a passage in the Metaphysics where Aristotle undertakes some religious archaeology. Our remote forefathers have, he says, handed down to us a tradition that the heavenly entities are gods and that the divine encompasses all nature. Later, however, mythical elements were added on 

- the zoomorphic and anthropomorphic gods of popular religion. But these were merely invented for ‘the multitude’ and because they were ‘useful’. (I take this to mean that the mob needed pretty statues to worship, and the state needed religion to control the mob.) But, he continues, we should separate the original ‘divine utterances’ from these later accretions . . . 

Aristotle has invented a new theology that seamlessly interweaves prehistoric superstition with cutting-edge science. He repeatedly refers to some antique belief about the gods — that they are located in heaven, are jmmortal or unchanging — and then shows, with a flourish, its consistency with cosmological theory. The reason, then — the only reason as far as I can tell ~ why Aristotle thinks that the celestial spheres are alive is because he thinks they're gods. 

Aristotle says that theology is not a branch of natural science. It is, in his terms, first philosophy, a branch of our metaphysics; natural science is second philosophy. Different domains of knowledge, he also says, should be kept firmly apart because they depend on different first principles. Yet in his relentless drive for intellectual Lebensraum he marches across any disciplinary frontier he pleases. He discusses the nature of the gods not only in the Metaphysics but also in The Heavens, The Soul, Generation e¢ Corruption and the Physics. They even appear in The Movement of Animals. 

It can hardly be otherwise since the functioning of the world depends on them in so many ways. The rotations of celestial spheres are the ultimate moving cause of all natural sublunary change. As moving causes the celestial spheres can keep the cosmos going whether they’re dead, alive or divine. But Aristotle also relies on them to give its creatures their goals; and for that they must be gods. Aeschylus died as the unwitting instrument of an eagle’s ends. Her goal (we may suppose) was merely to feed the tortoise to her ceaselessly ravenous brood. In doing so she sought to emulate the eternal motion of the stars — not the petrified perfection of crystalline spheres, but the immortality of living deities. All she sought was a little slice of for ever. So, looking to our mates, do we all. 

What do the motions of the god-spheres depend on? It may be thought that they depend on nothing: they're gods, after all. Besides, they’re built of aither that just naturally moves in a circle. That, indeed, seems to be the theory that Aristotle gives in The Heavens; in the Metaphysics and Physics, however, he gives another, or perhaps it’s just a shift in emphasis. In this second version celestial spheres do not move themselves. Their divinity is downgraded. Aither fades into the background and a host of mysterious entities appear on stage: the ‘unmoved movers’. 

The unmoved movers are the new deities. The spheres were almost mundanely comprehensible. Any science-fiction fan will take AU-scale sentient entities composed of exotic matter in his stride. The unmoved movers, by contrast, are gratifyingly abstract and paradoxical. There are said to be fifty-five of them, but also just one. They power the celestial spheres yet are utterly static themselves. They do this despite being indivisible, devoid of parts or even bodies. They are, in fact, immaterial. Aristotle means that they’re not made of any physical substance. 

The reason why there are so many unmoved movers is because each of them powers just one of the spheres in Aristotle’s geometrical model of the cosmos. All the stars, having a simple, unitary motion, can be assigned to one sphere. The moon, the sun and five planets, with their more complex motions, require another fifty-four. (Parsimony was never a strength of geocentric cosmologies.) The unmoved movers have their origin in Aristotle’s mature theory of motion. In this theory, still to be formulated when he wrote The Heavens, every motion requires a previous motion. Now aither spheres can no longer move themselves, they need to be kept in motion. But he doesn’t want an infinite regress of movers driving every sphere, so he gives each one an unmoved mover. The evolution of his physical theory, cosmology and theology are all inextricably intertwined. 

The unmoved movers obviously don’t pull or push their spheres around since then they'd be moving movers; besides, they’re immaterial so they can Instead each drives its sphere by being its object of love and desire. T sounds odd, but it’s a different kind of moving cause from simple phys causation for it depends on cognition. Aristotle says that the unmo movers ‘touch’ the celestial spheres, but are not touched by them. We - to understand this not as a literal, physical touch, but as a psycholog alteration — the sort of thing we mean when we say ‘I am touched by yo solicitude’ or ‘I am moved by her beauty.’ Even animals which can mov themselves ultimately depend on objects of desire to prod them into action. Love, it turns out, really does make the world go round.* 

Aristotle’s cosmos is now looking very busy. Add up all the spheres and their unmoved movers and he has 110 entities of varying degrees of materiality and divinity in Earth orbit. The reason that he can claim, within just a few paragraphs, that there are so many unmoved movers and also insist that there is only one is that, like so much in Aristotle’s world, they come in a hierarchy with one at the top. This, of course, is the unmoved mover responsible for the outermost stellar sphere. The ‘first unmoved mover’ has, 

in some sense, control of all the others. It may be their ultimate object of love and desire. It is Aristotle’s ultimate God. 

In the Metaphysics, Aristotle reveals, in sweeping periods, the purpose and nature of this entity: 

On such a principle [the first unmoved mover], then, depend the heavens and the world of nature. And it is a life such as the best which we enjoy, and enjoy for but a short time (for it is ever in this state, which we cannot be), since its actuality is also pleasure. (And for this reason are waking, perception and thinking most pleasant, and hopes and memories are so on account of these.) And thinking in itself deals with that which is best in itself, and that which is thinking in the fullest sense with that which is best in the fullest sense. And thought thinks on itself because it shares the nature of the object of thought; for it becomes an object of thought in coming into contact with and thinking its objects, so that thought and object of thought are the same. For that which is capable of receiving the object of thought, i.e. the essence, is thought. But it is active when it possesses this object. Therefore the possession rather than the receptivity is the divine element which thought seems to contain, and the act of contemplation is what is most pleasant and best. If, then, God is always in that good state in which we sometimes are, this compels our wonder; and if in a better this compels it yet more. And God is in a better state. And life also belongs to God; for the actuality of thoughtis life, and God is that actuality; and God’s self-dependent actuality is life most good and eternal. We say therefore that God is a living being, eternal, most good, so that life and duration continuous 

and eternal belong to God; for this is God. 

54U THE LAGOON 

This is what God does: he thinks. Normal thinking isn’t good enough for him, so he spends his time ‘thinking . . . thinking of thinking’ — noesis noeseos noesis. This is a God who knows neither love nor hate, who neither creates nor destroys, who does not save, condemn or even judge; this is a God utterly indifferent to Earthly affairs, yet upon whom, ironically, the very existence of the universe depends. 

In the Nicomachean Ethics Aristotle discusses the best sort of life to lead. The good life is obviously one of active virtue, and there are many ways in which virtue can be achieved ~ in politics or in the army, say. But the virtue that derives from such things is entirely utilitarian. The best way that a man can spend his life is in contemplation for that has no utilitarian goal; it’s pleasurable in itself. Elsewhere he relates a story. Someone asked Anaxagoras what was the point of being born, to which the great physiologos replied: ‘to study the heaven and order of the whole cosmos’. The answer rang true to Aristotle; he told the story at least twice. But he warns that none of us can ever achieve a life of pure contemplation. There are so many things, the mundane things of everyday life, and the human things — the sense is disparaging — that distract us from the divine life of the mind. Nevertheless we should ‘strain every sinew’ to ignore them and devote ourselves to pure reason. That is where true happiness lies. 

His works, pitiless in their detachment, show us what he means. He was, after all, a man who wrote of the press of sexual desire but not of Pythia, his long-dead Asian love; of the rise and fall of states but not of Alexander, the conquering boy whom he unleashed upon the world; of the very structure of reality while scarcely mentioning by name his teacher whose life’s work he effortlessly assimilated, appropriated and then destroyed. This is the life of reason — the scientific life ~ and, when you contemplate the rank of squat volumes, the shelves of papyrus scrolls that they once must have been, and the relentless march of his arguments page after page after page, you cannot help but feel that he has confused the causality; that he did not so much search for God as reconstruct Him in his own image. 

Yet there is another side to Aristotle’s God. For it is not only philosophers and scientists that can, indeed must, strive to be like Him; every natural thing partakes, to howsoever humble a degree, of His qualities. Indeed, it is only now that we can truly understand the meaning of the words with which Aristotle must have begun his great course, and with which I began this book: 

So we should not, like children, react with disgust to the investigation of less elevated animals. There is something awesome in all natural things. Some strangers, so the story goes, wanted to meet Heraclitus. 

They approached him but saw he was warming himself by the stove. ‘Don’t worry!’ he said. ‘Come on in! There are gods here too.” 

Even a cuttlefish is, in some way, divine. It is a sweet and solemn thought. Had I a God — had I a God — it would be Aristotle’s God. 

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fhe Roval Society’s propagandists — Thomas Sprat (History of the Royal saodty. 166-) and Joseph Glanvill (Plus Ultra, 1668) — echoed the charge. Glanvill was particularly caustic: ‘he [Aristotle] did not use and imploy fxperiments for the erecting of his theories; but having arbitrarily pitched his Theories, his manner was to force Experience to suffragate, and yield countenance to his precarious Propositions’. 

Bacon’s most serious charge was aimed at Aristotle’s explanatory sstem. Of the four kinds of causal explanations that Aristotle insists natural science demands, Bacon ruled two — the formal and final — illegitimate. Natural philosophy should concern itself with the properties and movements of matter and them alone. Explanations such as ‘the hairs of the eyelids are for a quickset and fence about the sight’, or ‘the firmness of the skins and hides of living creatures is to defend them from the extremities of heat or cold’, or ‘the bones are for the columns or beams, whereupon the frames of the bodies of living creatures are built’ were no part of science, but should be left to metaphysics. They were ‘remoras and hindrances to stay and slug the ship from further sailing’. They retard the search for the true, physical causes of things. 

Bacon’s attack on forms was subtler. It is, he said, futile to inquire into the form of a lion or an oak or gold or even water or air. To the degree that forms have a place in natural philosophy, they are only a list of the basic sensible properties of matter, heavy—light, hot—cold, hard—soft and the like. His formal properties were grounded in a particulate (in seventeenth-century jargon, ‘corpuscularian’) theory of matter. Heat, for example, is a type of motion found when particles are both set in motion and constrained in some way. He evidently envisioned a heat ‘law’ that relates particulate motion to temperature. Bacon sidestepped the question of how to get more complex objects — gold or lions — out of these basic properties: but, then, he was more concerned with providing general principles than usable theories. The thrust, however, was clear: a radical, un-Aristotelian, ontological reductionism in which there is room only for moving and material explanations. Bacon looked for a new philosophical champion in antiquity. Democritus. He would become the Attic poster boy of the new scientific age. 

Bacon’s aversion to Aristotle and Aristotelianism — he scarcely distinguishes the two — also stemmed from a particular vision of the purpose of science and its proper object of study. Its purpose, in Bacon’s view, was not merely to understand the world, but to change it; its proper object of study, then, was the artificial rather than natural. Bacon was a technology enthusiast. Aristotle’s philosophy, he said, was ‘strong for disputations and contentions; but barren of the production of works for the benefit of man’. Bacon demanded a new, mechanistic natural philosophy underpinned bya unified physics that would explain the movements of both natural and artificial objects. Newton would provide one. 

In biology, the cheerleader of mechanism was Descartes. Animals and plants, he declared, do not have souls — they are merely machines. This was the doctrine of the béte machine or beast machine. Descartes reduced the complex of Aristotelian changes to local motion alone, and founded his physiology on a corpuscularianism that he got from Gassendi and Beeckman. His mathematical physics was important, but his anatomy indifferent and he made no biological discoveries. (He contested with Harvey over the movements of the heart and lost.) His teleology was simply theistic. (Animals may be machines, but they are wondrous machines made by God.) But his explicit comparison of animals to automata resonated at a time when mechanical devices were proliferating. It did away with the obscurities of the Aristotelian nutritive and sensitive souls (rendered utterly opaque by the schoolmen) and gave a point of entry for experimental investigation. In 1666 the Danish anatomist Niels Stensen (Steno) wrote: 

No one but [Descartes] has explained all human function, and above all those of the brain, in mechanical fashion. Others describe for us man himself; Descartes speaks only of a machine, which at one and the same time shows us the inadequacy of others and points out a method of investigatir” the function of the parts of the body just as insightfully as he describes the parts of his mechanical man [italics mine]. 

The bete machine flexed its muscles and gave a lusty squall. 

Such then, in brief, are the intellectual currents that destroyed Aristotle’s science in the seventeenth century. His fortunes have varied since. Zoologists have always regarded him with affection. In the nineteenth century, Cuvier, Miller, Agassiz and many others even turned him into a bit of a cult.* To them, he was an illustrious forebear with a sharp eye for curious bits of zoology, an authority to wield against opponents, and even a fertile source of explanatory ideas — or so I have argued. In the eighteenth and nineteenth centuries, too, teleology was retrieved from the metaphysical and theological wastebasket to which Bacon and Descartes had consigned it. In some scientific circles, particularly German ones, final causes became respectable again. That was very Aristotelian. The consequences of that for his reputation were, however, ultimately malign. The association between teleology and vitalism revived and reinforced Bacon's old charge that Aristotle’s science was unmechanistic. Hans Driesch, that errant embryologist, even wrote a history of vitalism that commenced proudly with Aristotle. Twentiethcentury biologists would still be flogging vitalism long after it had expired. ‘And so to those of you who may be vitalists | would make this prophecy: what everyone believed yesterday, and you believe today, only cranks will believe tomorrow’ — Francis Crick in 1969. When, in 1954, Erwin Schrédinger published alittle book on ancient science he simply stopped with Democritus. Why bother going further? Aristotle had nothing to say to modern science. 

CX 

BACON AND HIS Successors said that Aristotle’s methods were wrong and that his explanations were too. Both charges are grave, but are they just? Our ideas of what constitutes scientific explanation, and how to achieve it, are ever changing. It may be, then, that we can see merits in Aristotle that our predecessors missed. Every generation must read Aristotle anew." 

That Aristotle made countless observations of the natural world ig obvious to anyone who reads his books — even the men of the Royal Society conceded so much. Should you read Aristotle’s biology, you may, however wonder why Bacon and Glanvill keep going on about his ‘experiments’ They said he did them but abused their results, using them merely to confirm what he knew or thought he knew. You, however, may be less dismayed by his abuse of experimental data than by its absence. 

The difficulty is merely semantic. In the seventeenth century ‘experiment’ meant any investigation of a natural phenomenon that involved some sort of intervention. Aristotle’s study of chick embryogenesis which involved finding eggs of just the right stage, carefully cutting open the shell and prodding the embryo to expose its heart is, in this sense, one. Starving and then strangling livestock to see their vascular systems is another. So are vivisecting tortoises and poking out the eyes of swallows. Aristotle sometimes indicates that he’s actually tried it out by using the term pepeiramenot: ‘Saltwater, when it turns into vapour, becomes sweet; and the vapour does not form saltwater when it condenses again. This we know by experiment. Or so pepeiramenoi is often translated. 

A modern scientist would take a more austere view. Such manipulations, he would say, are just observations made using a fancy technique. Experiments are defined not by their technique but by their logical structure. A true experiment is the comparison of a deliberately manipulated situation to an unmanipulated control for the purpose of testing a causal hypothesis. And Aristotle’s works, he would sadly conclude, are devoid of experiments of that sort.

&finally....

‘It has been said’, wrote Borges, ‘that all men are born cither Aristotelians or Platonists.’ Philosophers may wince at the opposition, but [ suspect it to be literally true. Plato invites us to the world of abstractions, Aristotle to the world of tangible things. You begin with particulars, a box of seashells say; gather them together and rearrange them endlessly in order to apprehend their logic and order. This apprehension, Aristotle says, is the gift of reason and the beginning of science. It is also where true beauty lies. This was inarticulatecly obvious to me when I was ten. As we age we become trapped by our habits of mind, by what we already know, as surely as fish are in the sea. Science, the glittering medium in which we swim, dictates what we see. That is how it should be and inescapably is, for no one sees the world unmediated by theory and expectation, 

Yet how we long to see it afresh. ‘For as the eyes of bats are to the blaze of day, so is the reason in our soul [oblivious] to the things that are most evident of all’ = Metaphysics 993b10. Aristotle, armed with the method that he discovered, that precarious combination of theory tempered by experience that is the essence of science, turned to a part of the world that no one had ever looked at before, described it, explained it and, as Thompson said, won for it a place in Philosophy. We can envy him for have doing so. Swept along in the seething currents of scientific progress we struggle to emulate him. But Aristotle shows us what we must do. 

And why. When I found the keryx it was lodged between two boulders. Its foot, as mottled as a leopard’s pelt, spilled from beneath its shell. Its tentacles were zebra striped. Never before had I seen one alive. The thick shell was covered with a filigree of bryozoans and a patchwork of coralline algae; its apex was grey and worn. It must have been very old. The great snail’s proboscis was stuck into a black sea urchin whose guts it was slowly rasping away. The sea urchin’s spines waved a last, futile defence, but its systems were failing fast. This is the world that Aristotle gave us: the vividly perceptible world of living things, whole and at home; the world that he enjoins us to love and understand. Aristotle wrote thousands of sentences, but one, the first of his Metaphysics, defines him: ‘All men, by nature, desire to know.’ Not all forms of knowledge, however, are equal — the best is the pure and disinterested search for the causes of the things. And, he has no doubt, searching for them is the best way to spend a life. It is a claim for the beauty and worth of science.