All of nature, whether an English woodland, the patch of Brazilian rainforest where Darwin sat to write his journal, or the biological diversity of a whole continent, is an apparently chaotic arrangement of organisms: flies next to birds next to worms, in trees, over grasses. In terms of ecological interactions – a kind of pattern or machine – they can be shown to make perfect sense. They constitute networks of spatial and temporal relationships behind which lie intertwining chains of cause and effect. With the discovery of order comes the possibility of finding lawfulness. For example, certain kinds of flowers (primroses, daffodils) grow in woodland and they ‘must’ flower before the leaves of the canopy emerge. Such flowers are almost invariably yellow and white, never red. Red flowers occur where levels of incident light are higher and they usually bloom in the open, later. Similarly, if one looks at physical structure (anatomy), which is what anyone sees first, an order appears. Of the birds in Britain or Europe or the world, all the woodpeckers fall together, separately from all the finches, the ducks and so on. It was perfectly obvious to every countryman that Queen Anne’s Lace, cow-parsley, wild parsnip and hemlock were all similar to each other, and different from celandines (which in turn seem closer to buttercups). If this is lawful, we can speculate about the causes.
Before anyone could make any sense out of the confused and confusing mass of new information about nature, the data had to be organised; what, for example, a woodpecker or a celandine is had to be defined. Let us imagine, for a moment, the contents of an automobile-parts warehouse dumped, thousands of different bits and pieces. You have to store them and then use them; the first steps must be to organise everything and put things on shelves where they can readily be found: all the brake pads in one place, the light bulbs in another. But cables would present a problem; whether to put brake cables with the other brake parts or with, say, the accelerator cables. There is probably no one perfect way to organise car parts.
Imagine, then, doing all this without any notion of what a car is. You couldn’t do anything logically unless you knew what the bits were for. You couldn’t discover what the bits were for until you had at least understood them enough to categorise them: a circle of ignorance. This was the problem for the natural philosophers who tried to categorise nature in order to understand it better and, not incidentally, to discover what it told them about the Creator. They had to create systems of classification that discovered patterns out of what would otherwise be a random arrangement of entities. For example, given a disassembled car one would quite easily work out from the external body panels that automobiles are bilaterally symmetrical, with a front and back, left and right. But then the five, rather than four, wheels with road tires would make no sense – that would require a new concept, that of the spare wheel. And the steering wheel would be baffling; one’s natural inclination to classify it with the other wheels would likely slow or even prevent any attempt to discover a different use for it. In the same way, when Aristotle made his first classifications of living things, he separated the whales from the other mammals: logical enough in a way. But he also correctly saw that whales were quite different from fishes, even though both lived in the sea. In any case, we can excuse Aristotle his errors, remembering the wise man who once said ‘never do anything for the first time’.
Ray’s passion to organise the facts of nature was not mere stamp collecting but a search for new, deeper truths. The patterns (classifications) that Ray and those following him established were philosophically powerful. A surprising depth of enquiry into the root causes of things is bound up in the apparently simple statement that the flightless dodo is related to the pigeon rather than the ostrich. Once one has found patterns in the distribution of different kinds of organisms in the world, one is naturally led to queries about the causes of those patterns. If God made them, then the patterns are a reflection of the symmetry and orderliness of God’s perfect mind. The sub-patterns might then be the result of God working out variations of different ideas – the idea of a worm, a woodpecker or a pigeon, for example. But this also depended on one of Ray’s greatest contributions, which was to establish the building bricks, or the least common denominators, out of which the great natural groupings of organisms are made. The early practice and theory of classification honoured the biblical practice of referring to distinct ‘kinds’ of creatures. We now call such entities ‘species’ and we are so used to the idea that each species of animal and plant is different from all others, and has its own name by which we distinguish it from its sisters, that we simply take for granted the concept of species itself, and even that names might be important. This concept of the species (‘species’ is the Greek for ‘kind’) was John Ray’s lasting contribution to natural science.
An instructive by-product of the identification of these patterns comes in the discovery of the very opposite. Because classifications aim to produce rational patterns, they prompt the investigator to query the apparently irrational that is also revealed. For example, many of the ‘natural’ groupings of animals and plants appear to have a geographical cause or at least a geographical consistency. This leads to new questions: Why, for example, are there no penguins in the Arctic, or polar bears in the Antarctic? One could understand why God might have created parrots for the tropics but why are hummingbirds only in the New World? Even more puzzling is the fact that Europe and North America each have eagles, kingfishers and woodpeckers – but different kinds. These inconsistencies (which dogged Darwin in his Cambridge and Beagle days and helped lead him to ideas of evolution) hinted of chance rather than purpose and any time the word ‘chance’ cropped up in 1800 (or 1700) it brought with it the possibility that the pattern was the result of contingencies in the underlying process, and particularly it raised the spectre of the ‘chance collisions of atoms’ and all the other Epicurean and Cartesian Second Causes.
Another difficulty slowly to emerge was that, with the identification of the species as the basic entity in classification, a circular argument had developed. On the one hand, one can only list and systematise discrete and fixed entities. One cannot systematise the constantly changing parts of a cloud or the molecules of steam escaping from a boiling kettle. On the other hand, the very fact of naming and classifying species established and reinforced their fixity. Immutability of species became both a necessary premise and a consequence of the science of classification. The very tools that opened up the world of biological diversity (by making it rational) tended to close off any discussions of its basis in fact (by denying the possibility of change). And of course this was a boon to theology. If they were created by the Almighty, the species of animals and plants on earth must today retain the individuality with which he originally endowed them. If God at creation ‘found them good’, that allowed (if it did not dictate) the logical conclusion that he made them fixed and immutable, unchanging and unchangeable. From then on, there was huge pressure to see species as real and immutable, despite all evidence to the contrary.
Those who argued the other case, as did fledgling evolutionists, a hundred years later were more easily dismissed. Even without attempts to interpret Genesis to that effect, the whole concept of God having created living organisms implied that they were perfect – a reflection of the perfection of God’s mind – and would not change. It must, therefore, have been more than a little disconcerting to the great eighteenth-century botanist Linnaeus and his contemporaries eventually to discover that species were not fixed after all. Indeed, the idea of fixed species flew in the face of common-sense experience with crossbreeding, both artificial