농생태학은 자연적인가? 자연적인 건 좋은 것인가?

"Agroecology" is a hugely important concept – a world-changer. We could reasonably argue that if agriculture and indeed if humanity and our fellow creatures – or for that matter the whole world – are to have a future at all, then it lies with agroecology. But as is always the case with such big and high-fallutin’ concepts the term itself, “agroecology”, has been picked up by all kinds of lobbies for all kinds of purposes. Corporate apologists have even argued that GMOs fit the agroecological bill because (allegedly, for a time, under certain conditions, sometimes) they make it possible to use less pesticide. But agroecology should mean that we should treat each farm as an ecosystem, and agriculture as a whole as a key component of the biosphere, as it so obviously is. Indeed, I like to argue that if we seriously want to practice agroecology then we must seek to emulate nature.

But here I have fallen foul both of professional, academic ecologists and of philosophers. First, say the ecologists, nature is not a good model for agriculture. Nature is in many ways disastrous. If we follow nature slavishly we will wreck agriculture and indeed the whole world in double quick time – even quicker than we are now. We have to accept that agriculture is an artefact and must always be artificial. We may contrive to make it more wildlife-friendly – but we won’t do this by imitating nature itself. That is romantic nonsense; the ramblings of greenies and hippies.  Neither can we simply seek to follow the general “principles” of nature. Nature does what nature does – this, that, and lots of other things as well. There are no coherent “ecological principles” – or none that can reasonably be applied to our own agricultural endeavours.

Then the philosophers suggest that to argue that nature is or must be a good model for us to follow is to fall foul of what the English philosopher G E Moore at the start of the 20th century called “the naturalistic fallacy”. Moore was talking not about farming but about morality: whether it is sensible to argue, as many do (or seem to) that good behaviour is natural behaviour: or at least, that whatever is unnatural is definitely morally bad. To argue that farming that follows nature is intrinsically good, or that high-tech methods that seem to override nature are ipso facto bad, is at best naïve, say the critics.

So let’s take these objections one at a time:

Is it wise for farmers to emulate nature ?

Most people seem to agree that if we, humanity, seriously intend to survive more than the next few decades in a tolerable state then we need agriculture that fulfils three prime conditions. First and most obviously it must produce enough food to sustain and keep contented a possible 9.5 billion people. Secondly, it must be sustainable: not fouling its own nest; able in principle to keep going indefinitely. Thirdly, it must be resilient — able to endure changing circumstances, or else to change direction rapidly. Many seem to leave “resilience” off the list although it must be clear by now even to the most obdurate that conditions, notably the climate, are changing; that the extremes and fluctuations of the past few years are the portent of decades and perhaps of centuries to come. Global warming is real and above all it means turbulence.

It’s in these specifics – productivity, sustainability, and resilience – and not from the vast, heterogeneous, arm-waving whole that we can and should learn from nature. For nature has been reasonably productive on this Earth without interruption for the past 3.8 billion years even though, in that time, the Earth’s climate has flipped at intervals from pole-to-pole ice to pole-to-pole tropics (or very nearly) and back again, while the continents have fragmented and re-convened and spun on their axes and peregrinated around the globe – all as changeable, at least in the long term, as can be conceived.

So what’s the objection? Well, for a start, nature isn’t always particularly productive compared to what is possible, and rarely seems to be maximally productive. After all, natural selection does not favour overall productivity of entire ecosystems. It works primarily at the level of the gene or of the individual creatures (opinions differ) within the ecosystem. Some individuals (or populations, or genes) will flourish at the expense of others and the overall output will fall short of what cool assessment would say is theoretically possible. In practical terms, a well-managed greenhouse is many times more productive than the surrounding fields and especially in these uncertain times the crops it harbours are surely more secure.

Neither are particular ecosystems always as sustainable or resilient as they may seem. There are spectacular collapses. Entire continents may be eroded away (Australia is the world’s exemplar) or obliterated by volcanoes (much of today’s India sits on top of a migrant chunk of Gondwana that was simply overwhelmed by lava around 60-plus million years ago) and we may conservatively estimate that the total of all species now on Earth is less than one ten thousandth of the variety that has existed since life began. Nature, in short, seems horribly careless; remarkably profligate.

But to suggest that we should emulate nature is not to imply a slavish replication of all that nature does. That indeed would entail a slaughter of the innocents and mass wipe-out in the style of Sodom, but on the grandest scale.  Rather, we should ask what nature does that we would find useful – and then see if we can work out how nature achieves each particular feat. This exercize proves highly instructive.

On a preliminary, significant point of detail — we do not need farming to bemaximally productive, any more than nature is. The recent claims of government and industry (with eager support from sections of academe) that we need to produce 50% more food by 2050 just to keep up with rising population and demand is pure hype; and the modern drive to maximize overall productivity at all costs is very destructive in many different ways — at best misguided and at worst frankly corrupt. The world already produces enough macronutrient (protein and food energy) to sustain 14 billion people which is twice the present population; and since the UN tells us that numbers are on course to level out at around 9.5 billion, we already produce 50% more than we will ever need. Certainly, farms need to produce more human food per hectare than wild ecosystems generally do – that is what farming is for – but we needn’t assume that it has to break all bounds, or to exceed nature’s own capabilities by orders of magnitude. We don’t actually need to produce 12 tonnes of wheat per hectare year after year, or cows that give 15,000 litres. Such productivity may win prizes and rosettes and may even be profitable so long as oil is relatively cheap but it has nothing to do with sound ecology or good sense and everything to do with runaway commerce that has been allowed to make its own rules, and with science that is funded by commerce and has lost its moral core. Well-tempered greenhouses cannot be the global norm, for all kinds of reasons. Most of agriculture must always be carried out in the rough and tumble of the great outdoors. Nature, in the whole wide spectrum of wild environments, rises spectacularly to the task. In short, nature is not maximally productive — but if our agriculture was as productive as nature can be in all the conditions of the real wild world, albeit tilted to meet human needs, we would not be doing badly.

The priorities in the decades and centuries to come are for sustainability and resilience – and here, overall, nature’s track record is fabulous. If we could keep going for 3.8 billion years as nature has done, and survive the heat and wet of the Eocene and all the deep freezes of the Ice Ages, then we, or our descendants, should be well satisfied. So while it may not be sensible simply to emulate nature in a broad-brush arm-waving way – given that nature is so various and seems so profligate – it is surely worth asking how nature manages the particular feats that are necessary to us. How, then, has it managed to be so sustainable and so resilient?

Which particular features of nature should we seek to emulate?

Four basic tricks contribute to the endurance and resilience of nature. First – diversity: plenty of species and plenty of genetic variation within species, all mixed and re-stirred by sex. Secondly: between individuals and the various species there is competition of course but overall there is synergy – what one creature excretes another regards as provender, and so on and so on, ultimately to the advantage of all. Thirdly, re-cycling is de rigueur — ecosystems in general are a mesh of cycles, of water, carbon, nitrogen, phosphorus, what you will. Everything goes round and round and anything that leaves the system sooner or later comes back in again. Finally, natural ecosystems in general are low-input. To be sure, some ecosystems borrow from others and so become high-input – like estuaries, where the riches of the land meet the riches of the sea (and the mud is thick with worms and bivalves, with a miscellany of waders to feed on them). Crucially, though, no wild ecosystem makes use of fossil fuel. All is powered by the Sun (with a bit of help from gravitation via the tides, and some geothermal heat).

These four basic qualities translate very smoothly into farming practice. The diversity of nature translates into polyculture: many different crops and classes of livestock on the same farm, all as genetically diverse as is compatible with practical husbandry (for if they are too diverse they are hard to harvest and to sell). Synergy is achieved by intermingling as in traditional mixed farming: clovers and other legumes in the pasture and cereals; whey fed to pigs; and so on. Re-cycling is an aspect of this synergy: the most obvious way to re-cycle is to manure the fields (albeit with refinements). Low input in general means organic. Organic husbandry should at least be the default position: organic should be what is done as a matter of course unless there is very good reason to do something else.  The energy required to run machines (for of course there should be machines) is low compared to the amount that goes into artificial fertilizers, pesticides, and herbicides, and can be kept much lower by conservative practices (including as little cultivation as possible). As a not inconsiderable bonus – and contrary to what we are usually told — the productivity of low-input mixed farms when well-managed, measured in food value per unit area, can be at least as high over time as that of monocultural high-input industrial farms.

Farms that follow such practices – all reflecting what nature does – can truly claim to be practicing agroecology. Agroecology in turn is the method of Enlightened Agriculture – informally but accurately defined as “farming that is expressly designed to provide good food for everyone without wrecking the rest of the world”. Agroecological practice is clearly innately complex and hence requires high standards of husbandry. So enlightened farms that practice agroecology must be skills intensive. Enterprises that are complex and skills intensive gain little or nothing from scale up and hence in general are likely to be small to medium sized. In short: enlightened farms that are designed to provide us all with good food far into the future, and which truly practice agroecology, are opposite in all significant respects from today’s industrialized farms that are anomalously called “conventional”.

For today’s industrial farms are not designed primarily to provide us all with good food and to look after the rest of the biosphere. They are geared unashamedly, and indeed as a matter of pride, to the maximization of short-term profit: increase of wealth, by whatever means, for unspecified purposes. To maximize wealth and to “compete” with everyone else worldwide who is urged to do the same, they must maximize output at minimum cost. To maximize output they apply as much fertilizer and the rest of the chemical arsenal as seems cost effective (though the emphasis is on seems). The inevitable surpluses are then fed to livestock, which is largely unnecessary (we can produce all the meat needed to sustain the great cuisines without feeding so much concentrate); or else they are burnt and called “biofuel”. To cut costs the industrialists cut labour to a minimum and then cut some more. People are replaced by machines. But machines are dumb and crude compared with people and without skilled husbandry the systems must be made as simple as possible – so the polyculture of the mixed farm gives way to monoculture; and the crops and livestock are bred to be as uniform as possible first to make them easier to handle and to sell (for supermarkets like large consignments of uniform produce delivered “just in time”) and also to bring each and every individual to the peak of biological possibility. In such systems there are huge advantages in scale up – and so these ultra-simplified monocultures and livestock factories are built and operated on the largest possible scale; and governments like Britain’s which run on the simple algorithms of the neoliberal market and high tech, and certain sections of academe who have found it advantageous to go where the money is, support them in all this — using our, taxpayers’, money, to help them on their way. These systems are clearly destructive and in many ways vile – and also, which is the point of this article, they are mostunnatural. They flout, absolutely, the principles of agroecology; and they flout the principles of nature – or at least the particular principles that have enabled nature to endure such hardships over such vast time.

Still, though, some apologists for industrial farming clearly believe that they are doing a good job – the best that can be done. These apologists include some professional biologists who question whether the particular attributes of nature that I have singled out here, and seem at least at first sight to account for its long-term success, are really what they seem.

Do the alleged attributes of nature really stand up to scrutiny? Are they really what we need?

The stand-out feature of agroecology is the emphasis on diversity. This above all makes it possible to produce good crops and livestock with low inputs, and reduces the impact on the local, wild environment, and makes the farm wildlife friendly. This too is what requires plenty of skilled people on board, so that the agroeco farm becomes a sociable place to work. But, some critics have asked, does nature really make the case for diversity? Does nature itself really need to be as diverse as it sometimes is? So do farms that aspire to be agroecological really need to be so diverse?

First, the critics point out, there are some very simple ecosystems out there with very few species that seem remarkably enduring – including the vast boglands of Siberia and elsewhere that are based almost entirely on sphagnum moss. Then there is the boreal forest of Canada, with only nine prevailing species of tree: eight conifers and the deciduous quaking aspen. Those forests came into being as soon as the ice of the last Ice Age retreated something more than 8000 years ago and presumably will last until global warming really begins to bite.

In the starkest contrast, the great equatorial forests that circle the globe harbour at least 90 per cent of the world’s species. The Neotropical forest, from Mexico down into Argentina and Chile, contains 30,000 species of tree, or so it’s estimated, with up to 300 different species per hectare. If there is a clear correlation between diversity and sustainability then, we might suppose, the tropical forest should be far older than the boreal. We might expect that it would extend back into the time of the dinosaurs, when the first flowering plants appeared on Earth.

In reality, though, or so it seems, all present-day ecosystems including the most diverse are fairly new. At least, the species they contain may be ancient (and in general the conifers of the high north and deep south are more ancient than the flowering trees of the tropics) but the particular assemblages and communities of creatures that make up any one ecosystem are all, or nearly all, less than 10,000 years old. For that, roughly, is when the latest Ice Age ended: and the Ice Ages (apparently at least 10 in the past two million years) changed everything. They smothered the high latitudes in ice, so virtually no terrestrial species could survive at all – so the whole of the boreal forest has come in since. They also changed the tropics from the continuous wet canopy we see to today to something far patchier, veering towards savannah. So the present rainforests too are nothing like as timeless as they seem. The principle extends offshore: the Great Barrier Reef and the world’s other great coral reefs, which are second in diversity only to tropical rainforest, cannot be more than 10,000 years old. They are no older than Jericho. It seems, then, that the remarkably simplified ecosystems of the north and the fathomless complexity of the tropics are of equal longevity. Certainly, there is no obvious statistical connection, on the grand scale, between stability, or sustainability, and diversity.

When we look more closely the principle still seems to hold. If any one species disappears in a tropical forest, or if some foreign invader comes in that happens to affect some vital food source, then hundreds of species may disappear in their wake.  An example of the latter is the European wasp in New Zealand, which eats the resin from the conifers, and so deprives a whole swatch of native species of their accustomed provender. Observations like this – the longevity of some simple systems and the vulnerability and flux in the most complex systems – again suggest no simple correlation between diversity and stability; and this in turn implies that the more complex systems are not necessarily more sustainable or resilient either.

But if we look more closely still, the picture is not so straightforward. Concealed within the big picture we find that diversity bring individual benefits that again are clearly salutary.

Notably – as no ecologist or epidemiologist or vet of any other kind of biologist that I have ever met denies – diversity protects against parasites, a general term embracing pests and pathogens. In general it is hard to be a parasite. You cannot, as a parasite, simply set yourself up as an all-purpose bad guy. Potential hosts go to great lengths to fend off parasites in a hundred different ways and to be successful, a parasite must find a way through the defences of each potential  host – with each one offering defences that are grossly or subtly different from everybody else’s. In Darwinian terms, each parasite must adapt to its intended host. So it is that human beings can walk through fields of cauliflower dripping with mosaic virus in perfect safety – and even through herds of cattle with foot and mouth disease. CMV and FMD just aren’t adapted to us (yet). In turn, cauliflowers can feel pretty safe from measles or ‘flu. All parasites, too, always need new hosts to jump to – for the ones they invade first are likely either to die or to become immune. Transmission is itself a problem – it may, for example, need compliant vectors such as aphids or mosquitoes (and the vectors too should usually be seen as victims). But the parasite also needs a local population of amenable hosts. CMVs need to be surrounded by more brassicas, and measles viruses needs a constant supply of innocents who have not been exposed before, or been vaccinated, and so have not acquired immunity. Some parasites – like the anthrax bacillus – are patient, and can hang around in the environment for years or even centuries, waiting for a new host to turn up. But a great many – including the viruses of measles and FMD – can’t. They need rapid access to a new host.

It follows, too, that if any one infected creature is not surrounded by others of its own kind that are vulnerable, or if there are specific barriers between the infectee and other potential hosts, then the parasite – or at least the local lineage of it – will die out. Contrariwise, a creature that is not infected should remain uninfected so long as it is not surrounded by others of the same kind who are themselves vulnerable. A parasite that invades an individual that is not surrounded by more, potentially vulnerable hosts cannot cause an epidemic; and populations that include some potentially vulnerable types but with a high proportion of immune types will be most unlikely ever to be infected at all, and are then said to have acquired “herd immunity”.

The general truth of all this is demonstrated a million times over in nature – and many times over in agriculture. So it is that the fungi and fungus-like organisms that cause diseases such a wheat rust and potato blight have evolved as factories for producing spores – billions upon billions of them. Yet most of those fungi or fungus look-alikes are not particularly common in the wild. Surrounded as they are by a mass of very different organisms, each posing different challenges, they need their extraordinary fecundity just to keep ticking along. But – as has been shown in millions of fields worldwide with all kinds of crops – when once those same parasites find themselves in a monoculture, where all the individual plants or animals put up similar defences, then – if they can get a foothold at all – they can run riot. The Irish (and elsewhere) potato famine of the 1840s and the various attacks of Southern Leaf Blight on American maize are among the most notorious examples.

By the same token, conservation biologists are worried that many populations of wild creatures these days are not only too small for comfort – a lack of breeding females in any one generation could be enough to finish them off – but are also too genetically uniform. Elephant seals, cheetahs, and African wild dogs are among the wild creatures that have been through narrow genetic “bottlenecks” in the past (or are still in them) and now are highly homozygous; and many other species, including African lions, are joining their ranks. So the few that are left are now more vulnerable than ever before. What biologist or farmer ever doubted any of this?

Indeed, the threat of parasites is and always has been so great that this alone seems to account for some of the greatest wonders of all of nature. So at the last count there were 130 qualitatively different theories in the literature to explain the huge variety of tropical trees – and one of the theories that has stood up best invokes the need to ward off parasites. Parasites, like all organisms, abound in the tropics – the living is easy – and trees, which cannot run from them, adapt to their presence by putting as much distance as possible between themselves and other trees of the same species – for example by enticing fruit bats to carry off their fruits, which they then spread far and wide. Other trees of different kinds spring up in the spaces between. on an even broader front: the great evolutionary biologist W D Hamilton argued that parasites explain the ubiquity of sex. For sexual reproduction requires enormous energy, it is potentially dangerous, and it is inefficient – for creatures that are not hermaphrodite and self-fertilizing (which includes all mammals and all wild birds) two consenting adults are needed to produce any one offspring. Given that asexual reproduction — spores and fission and parthenogenesis and all the rest – works perfectly well with only one parent, the sexual kind at best seems wasteful (as some feminists have been wont to point out). But, so biologists generally agree, the point of sex is not to facilitate reproduction but to achieve genetic mixing; and the main reason for mixing, so many have said, is to ensure that no two individuals in any one breeding population are identical; and the reason why that is so desirable, said Hamilton, is that it makes life hard for parasites. The ugly fact of parasites, then, seems to account for the phenomenon that dominates all nature, and is the greatest theme of literature.

The same kind of arguments apply to nutrients. Common sense and common observation suggest that collectives of different creatures, whether it’s antelopes and zebras on Serengeti or mixed flocks of foraging birds, make better use of available nutrients than single species do. The same applies to mixed herds and flocks of farm animals. Many an experiment both in the field and the laboratory (for example using populations of protozoans) confirms this general observation.

In short, I at least would argue that diversity can certainly be seen as a “principle” of nature. Sex is a device to achieve diversity within species, to which almost all creatures devote a great deal of energy, and many sacrifice their lives. Some creatures (like aphids and fungi) clone themselves now and again but in multicellular creatures this is rarely more than an ad hoc device to boost the numbers quickly. Almost all the self-cloners return to sex at judicious intervals. In agroecology, diversity is central: many different crops and classes of livestock, raised side by side: mixed cropping; intercropping; agroforestry; and genetic heterogeneity within each population.

The frenetic drive in industrial agriculture to achieve uniformity (the government’s “Foresight” report of 2011 on The Future of Food and Farming even put in a good word for animal cloning – doubtless inserted by some lobby that needed to be placated), and then to compound the nonsense by growing the maximally uniform crops on the largest possible scale, is perverse. The idea that industrial farming is in any worthwhile sense “modern” seems a gross misuse of language – since it flouts all the insights of modern biology. The hyper-modern extravagances of agrochemistry and biotech – ever-more ingenious pesticide and genetically uniform crops fitted with specific “resistance” genes – serve primarily to counter, up to a point, the dangers imposed by the past 100 years of industrial practice that flouts the lessons that nature so obviously teaches us. It is not at all obvious to me why we continue to afford the leaders of Britain’s agriculture as much respect as we do. one single argument – that diversity is better than uniformity – reveals that much or most of what has passed as modernity over the past century, and particularly over the past two decades, is the most absolute nonsense.

What, then, of the apparent stability, and hence the sustainability and resilience of sphagnum bogs and boreal forest – where there seems to be very little variety at all? There are several answers to this.

One (which may seem feeble but isn’t) is that these apparently simple ecosystems always occur under very special circumstances. The boreal forest is, above all, cold. Very few creatures can live there at all. The nonstop pressure from a host of parasites and their insect and other vectors simply isn’t there – or at least only seasonally, and briefly. In short (so many biologists argue) boreal forests don’t need immense variety to ward off pests because the weather does the work for them. Sphagnum mosses achieve the success they do because they too live in difficult environments and bring to bear a series of physiological tricks which they have mastered better than anyone else. Basically they live in bog – but, unlike most bog plants, like rushes and willows for example – they also help to create bog; because they hold vast quantities of water in their fronds which keeps the whole space boggy even in times of drought. They also produce an acid environment that keeps most other plants at bay.

But also: these apparently simple – at times almost monocultural – wild ecosystems are nothing like so simple as they look. In particular, the soil microbiota of boreal forest, permafrost or not, is wonderfully complex. All the boreal trees are highly mycorrhizal with literally thousands of different mycorrhizal species and many different types on any one tree at any one time. The nature of the ecological relationships between the different kinds of mycorrhiza is only just coming to light. Sphagnum bogs, too, may be far from uniform. About 120 different species are known and many different kinds may share any one patch – each kind with its own preferred range of pH. The bogs themselves play host to a wide range of specialist plants, from sundews to orchids.

In short, the simple ecosystems of northern forest and sphagnum bogs are nothing at all like the monocultures of annual plants on an industrialized arable farm with the carbon content of the soil approaching zero and no soil biota at all, while the sphagnum bog is far closer in number of species and general ecology to a traditional meadow than it is to an industrial ley. We cannot therefore justify agricultural monocultures by appeal to nature because, in reality, there are no natural ecosystems that are anything like as monocultural as is common in modern farming. We can, however, say that all the examples that nature does have to offer point us to towards diversity.Nothing – including all the experience of industrial agriculture – points us towards monoculture, except for the short term profits sometimes earned by a few people in the very special, hothouse economy that we have (temporarily) created, divorced from the rough and tumble of the natural world. Yet monoculture, on the largest possible scale, is the order of the day.

All the other prime features of agroecology can be similarly justified. Synergy becomes possible only when there is diversity. Re-cycling is an aspect of synergy. Low input farming becomes more feasible when many different species are benefiting from each other – efficiency of feeding, biological control of pests, and so on. All these features are evident in nature and can be learnt from nature. The bad things that nature seems to do (wiping out or covering up entire continents, for instance) we should not seek to emulate (although these in practice are what we do do, with carpet bombing and concrete and soil erosion and all the rest). Perhaps it is not wise to say, though, that agroecology should seek to “emulate” nature. “Emulate” in this context is intended simply to mean “learn from”: ask how nature does the things that seem to be good. But “emulate” can be taken to mean “replicate”; and uncritical replication of all that nature is capable of would indeed be foolish. on the other hand, no-one ever advocated such foolishness, or that we should abandon common sense. (I certainly didn’t).

What of the other, broader objection: that to take nature as a model is to fall foul of “the naturalistic fallacy”?

Does agroecology fall foul of the naturalistic fallacy?

Philosophers and theologians seem to have been asking for as long as they both existed in recognizable form whether nature is good or bad and whether, therefore, it is good or bad to behave “naturally”.

To begin with then – is nature, intrinsically and taken in the round, morally good or bad? The easy answer is, of course, that this is a silly question. Nature just is. The concept of morality cannot apply at all except to thinking entities that are capable of choosing between different courses of action. Since we, human beings, are the only Earthly creatures capable of making such choices (or so we tend to suppose) the concept of morality can apply only to us. To apply it to other creatures – cows or worms or mushrooms — makes no sense; and it certainly cannot or should not be applied to the world as a whole, full as it is of all kinds of entities, like rocks and rivers, that are not even sentient (although many a traditional tribe and some modern scientists would take issue with that).

The “naturalistic fallacy” is a similar kind of argument: it says in essence that the concept of goodness or badness simply cannot be applied to nature. We can doubtless trace the roots of this idea back a very long way but it is convenient to begin with David Hume who in A Treatise of Human Nature(1739) complained that authors commonly slide from observations of what is the case to statements about what ought to be, without explaining how they got from one to other. Yet, he says, “ … as this ought, or ought not, expresses some new relation or affirmation, ’tis necessary that it should be observed and explained; and at the same time that a reason should be given; for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.” Nowadays Hume’s argument is commonly summarized in the adage, “You can’t derive an ‘ought’ from an ‘is’”. The particular ｅxpression at issue here – “the naturalistic fallacy” – was coined by the early 20th century G E Moore who inPrincipia Ethica tried to root moral philosophy in fundamental principles. He concluded, in line with Hume, that nature cannot be taken as a moral arbiter. What’s natural and what’s good simply belong in two different categories.  To search nature for moral guidance is to embark on a wild goose chase.

All this argument is eminently rational and many have accordingly taken it to be unimpeachable: the last word. But actually it isn’t. I have so far come across three kinds of objections and doubtless there are many more.

First, there is the line of thinking mooted by Plato in the 5th century BC and continued by St Augustine in the 5th century AD. Nature is intrinsically good because God created it (Augustine) or at least gave shape to what already existed (Plato), and God (for both) is the source and the embodiment of all goodness, and what he makes or shapes is good by definition. They both acknowledged as indeed one must that bad things happen too – that there is frightful mishap and evil in the world – which they explained in different ways. one modern argument (which incorporates much of the ancient arguments) says that the bad things that happen naturally are the price that has to be paid for a universe that works at all. For example, tsunamis happen because of plate tectonics and plate tectonics is necessary because without it the Earth would be one solid, static rock like the moon and nothing would ever be recycled and life would be impossible. The bad things that human beings do are a matter of choice. Some people most of the time and all people some of the time choose to do bad things. But choice is possible because God gave us free will. His self-appointed task, after all, was to create a perfect world; and beings that do not have free will are inferior to those who do. So a perfect world must contain beings who are able to make their own decisions. Sometimes they will choose to do bad things – but again, that is the price that must be paid. In the perfect world everyone would choose to do good; but it has to be their choice. A world full of clockwork angels doing good because they were programmed that way, would be perfect to look at perhaps but internally flawed.

One objection to that kind of argument, of course, is that it is metaphysical. It employs arguments that are not ostensibly “rational” at all. It makes assumptions – notably to do with the existence of God – that cannot be justified simply by engaging what we think of as the rational mind. “Rational”, in practice, tends to mean “scientific” — based on repeatable, reliable, quantifiable empirical data and giving rise to hypotheses that can be tested by applying logical arguments which preferably (or indeed must) be mathematical. The existence or non-existence of God cannot be explored, and certainly not nailed down, by such methods. So if you insist, as many hard-headed people do, that only strictly “rational” (meaning scientific) arguments are permissible then the musings of Plato and Augustine and of all other metaphysicians and theologians are simply out of order.

Still, though, we can reasonably point out (with the stress on “reasonably”) that the absence of a clear, scientific demonstration is not in itself a good enough reason for rejecting any particular idea. We might argue, after all, that the appeal to science and logic is itself arbitrary – certainly not a bedrock guide to veracity. Maths itself, the great universal arbiter of science, is itself full of untestable assumptions, as was pointed out in the early 20thcentury (by Kurt Godel).

In the mid 19th century Cardinal Henry Newman argued along comparable lines. He conceded that there may indeed be no logical connection between what is and what ought to be, just as Hume demanded. But, he said, that doesn’t mean there isn’t a connection.  Often we are led from one idea to another not by one single thread of reasoning but by a whole series of smaller arguments or observations that all lead in the same direction and between them are as convincing as we can hope for. He made an analogy with a ship’s hawser. It is compounded only from short lengths of hemp or manila yet they hold the mightiest ships to the quayside even though no single thread runs all the way from the one to the other. There is a rough analogy here with the modern physical concept of non-linearity. By the same token, there may be no unimpeachably logical connection between nature and morality but many different notions and feelings prompt us to suppose that there is – and such feelings should not be ignored.

Feelings indeed, in making moral decisions, are vital. As Hume himself pointed out, “The rules of morality are not conclusions of our reason.” Yet they are none the worse for that for as he also said, “We speak not strictly and philosophically when we talk of the combat of passion and of reason. Reason is, and ought to be only the slave of the passions, and can never pretend to any other office than to serve and obey them.”

Putting all this together, we may indeed accept Moore’s condemnation of “the naturalistic fallacy” but what really counts in the end in matters of morality is what we feel to be the case — although we can, of course, and should, use reason to refine our feelings. Thus most of us do feel in our bones that although it is not good simply to do what comes naturally, it is especially bad to do things that seem to us to be unnatural. It is a particularly terrible thing, we feel, for parents to abandon their children – because it “goes against nature”. By the same token, successive popes (in line with statements by St Paul) have condemned both homosexuality and contraception on the grounds that they thwart God’s purpose. This is a dubious argument on several grounds but it shows, nonetheless, that appeals to what is “natural” do in practice play a very large part in practical moral thinking, despite Moore.

But there is also, strange though it may seem, a Darwinian and hence an unimpeachably biological reason for suggesting that nature is intrinsically good. Natural selection, after all, when you strip it to its bones – when you ask what part of the argument is unquestionably true – simply says that some creatures (or genes; it does not affect the argument) survive better than others; and that those that are better able to survive are more likely to produce offspring that those that are less able. Various people including Darwin speculated on the kind of characteristics that would promote survival and some (including pre-Darwinian scientists like the Scot, James Hutton) suggested commonsensically enough that gazelles that were fleet of foot would have a better chance in life than the slow-coaches, so that’s what natural selection should favour. Such arguments envisage that gazelles would constantly be competing with cheetahs or in some parts of their range with wolves – or indeed competing with their fellows to escape from cheetahs and wolves. Darwin himself saw competition as a key driver of natural selection – and this is what sticks in most people’s minds, including most biologists’ minds, when they think of natural selection.

But Darwin himself observed how often we see cooperativeness in nature – and professed to be puzzled by it. Yet if we ask, with a cool head, and without preconception, what is the best, general survival tactic of all we would, I suggest, conclude that it’s cooperativeness. Life as a whole, for all that it struck Tennyson as “red in tooth and claw” is fundamentallycooperative. Cooperativeness trumps competitiveness. Life must have begun as a cooperative between different classes of molecules of separate origins. The organism is a master-class in cooperation. So are ecosystems, taken all in all. So indeed is the universe. If it were not so, everything would fall apart.

All the great religions, at their core, agree that the greatest of all virtues is compassion. Compassion is the core of morality, as the present Dalai Lama constantly emphasizes. Compassion implies true concern for others, whether of the same or other species. This concern comes naturally to us. It is an evolved feature. The biological root of compassion, I suggest, is the desire to cooperate –  a desire favoured by natural selection because it leads to cooperativeness which is the principal survival tactic.

I developed that argument in my latest book, Why Genes are Not Selfish and People are Nice. Many no doubt will say it is naïve but no-one has yet knocked it down and it seems to me to provide a good defence – a biological defence – of the notion that nature is innately good, since nature is cooperative and cooperativeness leads to compassion and compassion is the core of goodness. So the argument vindicates, at least in part, the idea that it ought to be good to emulate nature.

But actually, we can cut through this whole convoluted line of thinking – one that has been going on for thousands of years and can never ultimately be resolved – simply by pointing out that the agroecologist’s appeal to nature has nothing to do with the naturalistic fallacy at all. The naturalistic fallacy is a about morals. Agroecologists do not seek to emulate nature because that is morally good and may ease their passage into Heaven, but because it works. The point is not moral, but practical. The gap between the actual and the moral which some have argued is unbridgeable does not actually need to be bridged. The high-sounding appeal to the naturalistic fallacy is simply not appropriate. I have argued the point here only because clever people have brought it up and stones like this should not be left unturned.

In short: we cannot and obviously should not seek to replicate all that nature does. That would be ridiculous (and of course impossible). But we can identify particular features of ecosystems that seem to be well worth trying to match: their commendable if rarely maximal productivity under all kinds of circumstance; their persistence; and their ability to adapt to changing conditions. These features (whatever the caveats and conditional clauses) seem to be related to their diversity, the synergies born of this diversity, and the generally low input – certainly the freedom from fossil fuels.

So I will continue to argue that farmers should emulate nature – though taking more care to point out that “should” is not meant in the moral sense, and “emulate” does not mean “slavishly mimic”.

Colin Tudge, February 14 2014