Holding such views, the Civil War, when it broke out in 1861, provided him with an opportunity to do something practical. True to his word, Holmes accepted a commission ‘in a spirit of moral obligation’.10 His very first engagement, the battle of Ball’s Bluff, on 21 October that year, was far from being a success: 1,700 Union soldiers made the advance across the river, but less than half returned. Holmes took a bullet near the heart, the first of three injuries he was to suffer in the war and these wounds, as Menand observes, shaped him. (His handwriting in his letters was less than perfect, he told correspondents, because he had to lie flat on his back.)11 Subsequently, although he might recount his fighting exploits from time to time, he never read histories of the Civil War.12 He knew what he knew and he had no need and no wish to revisit the horror. The Civil War was fought with modern weapons and pre-modern tactics. The close-order infantry charge was designed for use against the musket, a gun with a range of about eighty yards. Nineteenth-century rifles had a range of 400 yards. This accounts for the terrible carnage of the Civil War, which is still the war in which most American lives have been lost and why it had such an effect on Holmes and others.13
Amid the carnage, he learned one thing that was to remain with him all his life. It was a distrust of absolutes and certainty, a conviction that ‘certitude leads to violence’.14 He looked about him and observed that, although the abolitionists in 1850 appeared to many Northerners as subversives, by the end of the war ‘they were patriots’. He concluded from this that ‘There is no one way that life must be.’15 This guided him and formed him into the wise judge that he became. This wisdom emerged in his great book The Common Law,16 which began life as the Lowell Lectures at Harvard University, all twelve given before a full house, where he spoke without notes.17
His biographer Mark DeWolfe Howe says Holmes was the first lawyer, English or American, to subject the common law to the analysis of a philosopher and the explanation of an historian.18 The philosophical brilliance of Holmes was to see that the law has no one overriding aim or idea. (This was the idea he brought from the disaster of the Civil War.)19 That it had evolved pragmatically.20 Every case, in terms of facts at least, is unique. When it reaches court, it is swept up in what Menand calls a ‘vortex’ of intentions, assumptions and beliefs. There is, for example, the intention to find the solution that is just in this case. At the same time, there is an intention to arrive at a verdict that is consistent with analogous cases in the past. There is also the intention to arrive at a verdict that will be most beneficial to society as a whole – the result that will deter others.21 Then there are a number of less pressing aims, which also impinge on a verdict, some of which, Holmes conceded, are unvoiced. These may include a wish to redistribute costs from parties who can’t afford them (often victims) to parties who can (often manufacturers or insurance companies). ‘However over this whole weather pattern – all of which is in motion, so to speak, before any case ever arises – is a single meta-imperative: not to let it appear as though any one of these lesser imperatives has decided the case at the blatant expense of the others. A result that seems just intuitively but is admittedly incompatible with legal precedent is taboo; the court does not want to seem to excuse reckless behaviour (like operating a railroad too close to a heavily populated area), but it does not want to raise too high a liability barrier to activities society wants to encourage (like building railroads).’22
Holmes’ genius was to face the fact that there are no hard-and-fast distinctions in any of these areas. This was made plain in a sentence that became famous, near the opening of The Common Law, where he said ‘The life of the law has not been logic; it has been experience.’23 He thought it was his job to speak harsh truths, not give way to historical legends.24 His argument was that, for the most part, common law judges make up their minds first and come up with ‘a plausible account’ of how they got there afterwards. He even allowed that there were ‘unconscious’ influences on a judge, an early and interesting use of the word.25 Holmes wasn’t saying that judges are wayward, random or even idiosyncratic in their pronouncements. He just wasn’t sure that experience is reducible to general abstractions, even though human beings spend so much time trying to do just that. ‘All the pleasure of life is in general ideas,’ he wrote in 1899, ‘but all the use of life is in specific solutions – which cannot be reached through generalities any more than a picture can be painted by knowing some rules of method. They are reached by insight, tact and specific knowledge.’26 He then built on this idea of experience to arrive at his most important contribution to civil law – his invention of the ‘reasonable man’. Holmes thought that the point of experience is that it is ‘collective and consensual’, social not psychological. This goes to the heart of modern liability theory and is one of the main points where the law treats the question: how are we to live together? In the classic case, as Menand puts it, someone is injured as a result of what someone else does, giving rise to the question: what brings about civil liability? Traditionally, three arguments are brought to bear on this. One, it is enough to prove causation. All citizens act on their own responsibility; therefore they are liable for any costs their actions incur, whether they could have foreseen the consequences or not. This is ‘strict liability’. Two, a citizen is liable for injuries he or she intended but not for those never contemplated. Legally this is called mens rea – the doctrine of ‘the guilty mind’. Third, there is the argument of negligence: even if a citizen, in acting in a particular way, never anticipated the possibility of injury to anyone, that person is liable anyway, if the action were careless or imprudent.27
Holmes’ contribution in this area was to replace the traditional legal terms ‘guilt’ and ‘fault’ with words like ‘carelessness’ and ‘recklessness’.28 He thought that by doing this, it would help make clear what we mean by behaviour that counts as reckless or careless. The main question, as he saw it, was to identify what was and what wasn’t the ‘permissible by-product’ of any activity. His answer, he said, was ‘experience’, and his achievement was to define this ‘experience’.29 What he meant by it, in this context, he said, is that of ‘an intelligent and prudent member of the community’. Law, he said, was not a ‘brooding omniscience in the sky’; it had to operate according to the precepts of an ‘average’ member of society, best exemplified by a jury.30 ‘When men live in society,’ Holmes insisted, ‘a certain average of conduct, a sacrifice of individual peculiarities . . . is necessary to general welfare.’ Thus it was the ‘reasonable man’, his beliefs and conduct, that governed Holmes’ understanding of liability. Now this is, as Menand also points out, a statistical fiction and the ‘legal cousin’ of Adolphe Quetelet’s homme moyen. ‘The “reasonable man” knows, because “experience” tells him, that a given behaviour in a given circumstance – say, taking target practice in a populated area – carries the risk of injuring another person.’31
Holmes also said at one point that a judge ‘should not have a politics’. Yet he himself was in favour of capitalists, as risk takers and wealth generators, and there were those who thought that his arguments actually moved the law away from the theory of strict liability towards that of negligence, which made it easier for big businesses to escape their ‘duty’ to workers and customers. ‘Nevertheless, in his theory of torts, Holmes did what Darwin did in his theory of evolution by chance variation and Maxwell did in his kinetic theory of gases: he applied to his own special field the great nineteenth-century discovery that the indeterminacy of individual behaviour can be regularised by considering people statistically at the level of the mass.’32 This was a crucial step forward in the democratisation of law.