Yet for all its astonishing range of esoteric reference and example, much of Instruments of Darkness struck me as disconcertingly familiar. It concerns witchcraft in England between 1550, when the first anti-witch statute had lately been promulgated, and 1750 when the last statute had recently been repealed. Englanders 300 years ago were "neither particularly stupid nor particularly wicked". They worked, as the historians say, within the mind-set of the time, and most of them were animated by genuine fear, honest religious conviction, and a sense of duty. Nor were they always cruel. Most alleged witches were acquitted, many more got off with light sentences, and, contrary to popular legend, probably not more than 500 were executed.
Sharpe is adamant that witch-persecution in England was not, as some feminists imply, part of the cosmic male conspiracy against women - most prosecutions in fact began with women accusing women. It is true, though, that the vast majority of supposed witches were female, perhaps because the realm of the occult was one sphere in which women were able to command some degree of power. All too often witches were poor old ladies, stooped and bent not with evil but with poverty and age, cherishing their cats and dogs not as agents of the devil, but as friends in their loneliness. They were reviled and hated because they were different; the growths of old age on their bodies were supposed to be the teats by which their familiars sucked their blood; and often enough, no doubt, genuine fear of their powers led to genuine bewitchment.
But has the popular mind-set really changed? Time and again, as I read this scrupulously balanced work of scholarship, I was reminded of contemporary parallels. Anorexia and bulimia sound to me remarkably like what our forebears would have called "Possession" - inexplicable depression, vomiting and wasting away, popularly attributed to witchcraft but often, as even some 17th-century observers realized, brought on by a young woman's psychological need for love and attention. The old belief in the beneficent powers of "white witches", and for that matter in the malicious powers of black ones, was no different in kind from today's widespread trust in faith healers. For the old rumours of covens of witches in woodland sabbat, read the new whispers about internet forums of Satanists.
Then again the attitudes of different parts of society have not greatly shifted. By the nature of things much of the religious establishment is as superstitious now as it was then. It may not be so intolerant of heresy, but it is still prepared to exorcise demons with mumbo-jumbo, and to accept the existence of an Evil Being: John Wesley himself used to argue that denying the reality of witchcraft meant denying the reality of the Devil. Then as now, for the most part the English judiciary did its best to play fair. Supposed witches were often given the benefit of the doubt, intellectual honesty overcame legalism and populist clamour: "there is no law against flying", bravely pronounced Sir John Powell, when poor Jane Wenham ("a fairly typical witch", says Dr Sharpe) was accused of habitually whizzing about the night skies. Even in the 16th century defamation suits were popular - too carelessly calling somebody a witch could prove expensive in the courts.
Petty authority, by and large, seems to me just as loveless today as it was in the days of the witch-hunts. Sleep deprivation, one of the methods of making witches confess, has not gone out of fashion among modern torturers, and many a police interrogator, I do not doubt, would like to be able to throw a suspect into a pond to see if she sank or floated, or to keep her naked on a stool in the middle of the interrogation room for two or three days at a time. There is nothing anachronistic about the pounds 4. 7s charged for "diet and wine" by the indefatigable witch-investigator Matthew Hopkins, when he was on the job in Aldeburgh in 1646.
Worst and most obvious of all, nothing much has changed in the attitudes of the rabble. Mob-influence seems to have been almost as powerful three centuries ago as it is in contemporary Britain. The persecution of witches all too often began in local gossip and malicious innuendo, and prying, suspicious, envious or contemptuous neighbours were generally the first informants - the very people who would now get on to the hot line to denounce a social security infringment. They were abetted by zealot-priests or self-important local officials, just as they are now inflamed or supported by the loutish tabloid press. They howled, gaped and swore at alleged witches just as they now spit their hatred at alleged sex offenders. They demanded executions as they now call for ever heavier prison sentences. They were encouraged by just the same purveyors of the occult as now feed their appetites for fortune-telling and nonsensical astrology.
And the witches themselves? I would guess that some old ladies still stick pins in images of their la-di-da neighbours, and perhaps there are even a few - who knows? - still suckling their toads at midnight. They are no danger to us. It is still the witch-hunters we have to guard against.