First, the societies that did not have it:
1. Ancient Israel:
And Abraham drew near and said, Wilt thou also destroy the righteous with the wicked? Peradventure there be fifty righteous within the city: wilt thou also destroy and not spare the place for the fifty righteous that are therein? That be far from thee to do after this manner, to slay the righteous with the wicked: and that the righteous should be as the wicked, that be far from thee: Shall not the Judge of all the earth do right? And the Lord said, If I find in Sodom fifty righteous within the city, then I will spare all the place for their sakes.
And Abraham answered and said, Behold now, I have taken upon me to speak unto the Lord, which am but dust and ashes: Peradventure there shall lack five of the fifty righteous: wilt thou destroy all the city for lack of five? And he said, If I find there forty and five, I will not destroy it. And he spake unto him yet again, and said, Peradventure there shall be forty found there. And he said, I will not do it for forty’s sake. And he said unto him, Oh let not the Lord be angry, and I will speak: Peradventure there shall thirty be found there. And he said, I will not do it, if I find thirty there. And he said, Behold now, I have taken upon me to speak unto the Lord: Peradventure there shall be twenty found there. And he said, I will not destroy it for twenty’s sake.
And he said, Oh let not the Lord be angry, and I will speak yet but this once: Peradventure ten shall be found there. And he said, I will not destroy it for ten’s sake.
— Genesis 18:23-32
2. Classical Athens:
Men of Athens, do not interrupt, but hear me; there was an agreement between us that you should hear me out. And I think that what I am going to say will do you good: for I have something more to say, at which you may be inclined to cry out; but I beg that you will not do this. I would have you know that, if you kill such a one as I am, you will injure yourselves more than you will injure me. Meletus and Anytus will not injure me: they cannot; for it is not in the nature of things that a bad man should injure a better than himself. I do not deny that he may, perhaps, kill him, or drive him into exile, or deprive him of civil rights; and he may imagine, and others may imagine, that he is doing him a great injury: but in that I do not agree with him; for the evil of doing as Anytus is doing – of unjustly taking away another man’s life – is greater far. And now, Athenians, I am not going to argue for my own sake, as you may think, but for yours, that you may not sin against the God, or lightly reject his boon by condemning me.
— Socrates, Apologia, 5th Century BC
3. Post-classical Athens, as Aristotle goes grapple, grapple and does not get it quite right:
It is a serious matter to decide that a slave is free, yet it is much more serious to convict a freeman of being a slave [4th Century BC].
Next, the societies that did have it:
1. Republican Rome:
I would rather ten guilty persons should escape, than one innocent should suffer.
— Cicero (attributed in Sallust, but he may not have said it first); 1st Century BC
2. Imperial Rome:
A person ought not to be condemned on suspicion; for it is preferable that the crime of a guilty man should go unpunished than an innocent man be condemned.
— Trajan, 2nd Century AD
3. Medieval Judaism:
The Exalted One has shut this door against the use of presumptive evidence, for it is better and more satisfactory to acquit a thousand guilty persons than to put a single innocent man to death once in a way.
— Maimonides, 12th Century
4. Anglo-Saxon England:
When the jurors were in doubt about their verdict, for in cases of doubt one should rather save than condemn; it is better to accuse no innocent man, nor conceal any guilty one.
— King Alfred, 9th Century
5. Medieval England:
Indeed I would rather wish twenty evil doers to escape death through pity, than one man to be unjustly condemned.
Chief Justice John Fortescue, 1471
6. Enlightenment England:
Better that ten guilty persons escape than that one innocent suffer.
A false impression
The above selection of quotations is apt to give one a false impression, one I hope to correct. The correction is, however, indicative of real human progress. We should be proud of it.
The false impression is conveyed in all the Roman and English quotations: they make it look as though we have always had the presumption of innocence, and we have often set N at about 10. We will let 10 guilty men go free rather than convict a single innocent. I could have found many more English and Roman lawyers stating something similar: Matthew Hale and Ulpian, say. I could also have crossed the Atlantic to the United States, citing a veritable galaxy of American jurists.
However, the English and the Romans are outnumbered by societies — even very great ones — that behave as the ancient Israelites and Athenians did. For most of human history, we human primates have believed that where there is smoke there is fire. When we have accused people of wrongdoing, we have considered our accusations just because the accused ‘have it coming to them’. Ulpian — the first lawyer to think deeply and critically about the presumption of innocence — realised that the presumption of innocence represents a decisive rejection of the ‘just world’ hypothesis, and that this rejection takes real intellectual effort.
The just world
This is because people are uncomfortable believing that suffering is often random, that sometimes bad things happen for no reason at all. Instead, we prefer to believe that people must have done something to deserve what they get. This is obviously a reassuring and comforting belief, which explains its wide appeal. (‘If bad things only happen to those who deserve them, and I’m a good person, then I can be sure that nothing bad will happen to me‘, Ulpian notes at one point)*. For us moderns, belief in the just world can be thought of as a failure to apply the null hypothesis in the moral domain: rejecting the explanation of chance, we prefer to believe that everything that happens is deserved. As should be obvious, the just world hypothesis manifests as the doctrine of karma in a number of religious traditions.
*It is perhaps worth noting that Ulpian, the Prefect of the Praetorian Guard, was later fragged by his own men, in part because he restrained their use of torture.
It was Robert Nozick – in Anarchy, State and Utopia – who observed that any criminal justice system unwilling to confine N would be one that had no system of punishment at all. This recognises a tradeoff, a balancing act, and the impossibility of perfection. It recognises, too, that every time a guilty person is acquitted the law, in a sense, has failed the community it exists to serve. It also explains why N tends to float up and down throughout English and Roman history. 10 is the most common figure, but the Romans often expressed themselves, like Trajan, in terms of a 1-for-1 trade. Matthew Hale spoke of 5-for-1, and in a 1951 judgment — R v Patel  All E.R. 29 — the Court of Criminal Appeal noted the difficulty of ‘trying to steer between the Scylla of releasing to the world unpunished an obviously guilty man and the Charybdis of upholding the conviction of a possibly innocent one.’
Confining N is therefore difficult. Like Nozick, Jeremy Bentham worried that a justice system that failed to punish the genuinely guilty would fail as surely as a justice system that routinely punished the genuinely innocent:
We must be on guard against those sentimental exaggerations which tend to give crime impunity, under the pretext of insuring the safety of innocence. Public applause has been, so to speak, set up to auction. At first it was said to be better to save several guilty men, than to condemn a single innocent man; others, to make the maxim more striking, fix the number ten; a third made this ten a hundred, and a fourth made it a thousand. All these candidates for the prize of humanity have been outstripped by I know not how many writers, who hold, that, in no case, ought an accused person to be condemned, unless evidence amount to mathematical or absolute certainty. According to this maxim, nobody ought to be punished, lest an innocent man be punished.
When discussing N, then, it is wise to keep both Bentham and Ulpian in mind, and also to remember that our justice system can be polluted by awful attitudes dragged across from other belief systems. One of the reasons rape is so fraught is not just because, as Ulpian observed, it involves the criminal expression of something that would otherwise be both a perfectly legal and enjoyable act. It is also fraught because the civilisation that came after Ulpian’s decided that there was something inherently wrong with women: they entered the justice system disabled by something that was in them, and that they could not change. This would have flummoxed Ulpian, and reflects badly on we who came after. The doctrine of original sin is, after all, a particularly nasty manifestation of the just world hypothesis.
We must take care, then, not to make decisions in advance stipulating that people have something about them that disables them before they enter the justice system. For the longest time, the people entering the portals of justice with a presumption operating against their character were all women. As we became monotheists, we added gays, Jews, and black people to the there’s something funny about you list. We then spent the best part of 200 years removing all those groups from the same list. This removal is far from perfect, of course, although it is well progressed in the developed world.
However, as part of this process, we must also take care not to add new people and new characteristics to that list in lieu of the old ones. That is, I believe, what happened in the rush to judgment in the Duke Lacrosse case: well, they had it coming, didn’t they, white and privileged…
What if I told you that the bulk of crime in Britain was committed by 100,000 known and named individuals with a list of previous convictions that makes them ridiculously easy to trace? And what if I added that we could arrest the lot of them, lock them up without charge, and reduce the country’s crime rate almost to zero overnight?
I hope you’re not tempted, but it is true that we know who most of the future criminals are, where they live, what race they are, and lots of other things about them. And it is also true if we decided to revert to the world of Ancient Israel or Classical Athens — just lock ’em up, where there’s smoke there’s fire, of course they’ll do it again — we would indeed reduce our crime rate to trivial levels (it has in fact been falling for a long time).
However, there comes a point where reducing crime beyond a certain level enlivens the law of diminishing returns: not only does it become prohibitively expensive, but fundamental aspects of our society and justice system have to be bent out of shape in order to achieve it. I seldom recommend the use of popular culture to teach a legal lesson, but maybe it is worth watching this film again:
We do not live in a just world. We ought not to ascribe characteristics to people before applying justice to them (otherwise it will soon cease to be justice). And we should be proud of the fact that we have had the wit to adopt — for the most part — a legal minority position that is striking in its generosity of spirit. Because I don’t buy the just world hypothesis, I don’t think that choice was inevitable. We so easily could have gone the other way.