The Evolution of Everything: How Small Changes Transform Our World. Matt Ridley

always invented, rather than that it evolved. As the economist Don Boudreaux has argued, ‘Law’s expanse is so vast, its nuances so many and rich, and its edges so frequently changing that the popular myth that law is that set of rules designed and enforced by the state becomes increasingly absurd.’

      It is not just the common law that evolves through replication, variation and selection. Even civil law, and constitutional interpretation, see gradual changes, some of which stick and some of which do not. The decisions as to which of these changes stick are not taken by omniscient judges, and nor are they random; they are chosen by the process of selection. As the legal scholar Oliver Goodenough argues, this places the evolutionary explanation at the heart of the system as opposed to appealing to an outside force. Both ‘God made it happen’ and ‘Stuff happens’ are external causes, whereas evolution is a ‘rule-based cause internal to time and space as we experience them’.

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       The Evolution of Life

      A mistake I strongly urge you to avoid for all you’re worth,

      An error in this matter you should give the widest berth:

      Namely don’t imagine that the bright lights of your eyes

      Were purpose made so we could look ahead, or that our thighs

      And calves were hinged together at the joints and set on feet

      So we could walk with lengthy stride, or that forearms fit neat

      To brawny upper arms, and are equipped on right and left

      With helping hands, solely that we be dexterous and deft

      At undertaking all the things we need to do to live,

      This rationale and all the others like it people give,

      Jumbles effect and cause, and puts the cart before the horse …

      Lucretius, De Rerum Natura, Book 4, lines 823–33

      Charles Darwin did not grow up in an intellectual vacuum. It is no accident that alongside his scientific apprenticeship he had a deep inculcation in the philosophy of the Enlightenment. Emergent ideas were all around him. He read his grandfather’s Lucretius-emulating poems. ‘My studies consist in Locke and Adam Smith,’ he wrote from Cambridge, citing two of the most bottom–up philosophers. Probably it was Smith’s The Moral Sentiments that he read, since it was more popular in universities than The Wealth of Nations. Indeed, one of the books that Darwin read in the autumn of 1838 after returning from the voyage of the Beagle and when about to crystallise the idea of natural selection was Dugald Stewart’s biography of Adam Smith, from which he got the idea of competition and emergent order. The same month he read, or reread, the political economist Robert Malthus’s essay on population, and was struck by the notion of a struggle for existence in which some thrived and others did not, an idea which helped trigger the insight of natural selection. He was friendly at the time with Harriet Martineau, a firebrand radical who campaigned for the abolition of slavery and also for the ‘marvellous’ free-market ideas of Adam Smith. She was a close confidante of Malthus. Through his mother’s (and future wife’s) family, the Wedgwoods, Darwin moved in a circle of radicalism, trade and religious dissent, meeting people like the free-market MP and thinker James Mackintosh. The evolutionary biologist Stephen Jay Gould once went so far as to argue that natural selection ‘should be viewed as an extended analogy … to the laissez-faire economics of Adam Smith’. In both cases, Gould argued, balance and order emerged from the actions of individuals, not from external or divine control. As a Marxist, Gould surprisingly approved of this philosophy – for biology, but not for economics: ‘It is ironic that Adam Smith’s system of laissez faire does not work in his own domain of economics, for it leads to oligopoly and revolution.’

      In short, Charles Darwin’s ideas evolved, themselves, from ideas of emergent order in human society that were flourishing in early-nineteenth-century Britain. The general theory of evolution came before the special theory. All the same, Darwin faced a formidable obstacle in getting people to see undirected order in nature. That obstacle was the argument from design as set out, most ably, by William Paley.

      In the last book that he published, in 1802, the theologian William Paley set out the argument for biological design based upon purpose. In one of the finest statements of design logic, from an indubitably fine mind, he imagined stubbing his toe against a rock while crossing a heath, then imagined his reaction if instead his toe had encountered a watch. Picking up the watch, he would conclude that it was man-made: ‘There must have existed, at some time, and at some place or other, an artificer or artificers, who formed [the watch] for the purpose which we find it actually to answer; who comprehended its construction, and designed its use.’ If a watch implies a watchmaker, then how could the exquisite purposefulness of an animal not imply an animal-maker? ‘Every indication of contrivance, every manifestation of design, which existed in the watch, exists in the works of nature; with the difference, on the side of nature, of being greater or more, and that in a degree which exceeds all computation.’

      Paley’s argument from design was not new. It was Newton’s logic applied to biology. Indeed, it was a version of one of the five arguments for the existence of God advanced by Thomas Aquinas six hundred years before: ‘Whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence.’ And in 1690 the high priest of common sense himself, John Locke, had effectively restated the same idea as if it were so rational that nobody could deny it. Locke found it ‘as impossible to conceive that ever bare incogitative Matter should produce a thinking, intelligent being, as that nothing should produce Matter’. Mind came first, not matter. As Dan Dennett has pointed out, Locke gave an empirical, secular, almost mathematical stamp of approval to the idea that God was the designer.

      Hume’s swerve

      The first person to dent this cosy consensus was David Hume. In a famous passage from his Dialogues Concerning Natural Religion (published posthumously in 1779), Hume has Cleanthes, his imaginary theist, state the argument from design in powerful and eloquent words:

      Look around the world: Contemplate the whole and every part of it: You will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines … All these various machines, and even their most minute parts, are adjusted to each other with an accuracy, which ravishes into admiration all men, who have ever contemplated them. The curious adapting of means to ends, exceeds the productions of human contrivance; of human design, thought, wisdom, and intelligence. Since, therefore the effects resemble each other, we are led to infer, by all the rules of analogy, that the causes also resemble. [Dialogues, 2.5/143]

      It’s an inductive inference, Dennett points out: where there’s design there’s a designer, just as where there’s smoke there’s fire.

      But Philo, Cleanthes’s imaginary deist interlocutor, brilliantly rebuts the logic. First, it immediately prompts the question of who designed the designer. ‘What satisfaction is there in that infinite progression?’ Then he points out the circular reasoning: God’s perfection explains the world’s design, which proves God’s perfection. And then, how do we know that God is perfect? Might he not have been a ‘stupid mechanic, who imitated others’ and ‘botched and bungled’ his way through different worlds during ‘infinite ages of world making’? Or might not the same argument prove God to be multiple gods, or a ‘perfect anthropomorphite’ with human form, or an animal, or a tree, or a ‘spider who spun the whole complicated mass from his bowels’?

      Hume was now enjoying himself. Echoing the Epicureans, he began to pick holes in all the arguments of natural theology. A true believer, Philo said, would stress ‘that there is a great and immeasurable, because incomprehensible, difference between the human and the divine mind’, so it is idolatrous blasphemy to compare the deity to a mere