There were many sources for the ideas held by these prophets but two lay at their origin. One was the Book of Revelation (famously characterised by Thomas Jefferson as the ravings of a maniac) and the other was a number of apocalyptic writings in the Middle Ages known as the Sibylline Oracles. The earliest of these date from the death of the Emperor Constantine, to whom the Sibylline authors attached an eschatological significance. 'Thanks to them , in the imagination of Christians for more than a thousand years the figure of the warrior-Christ was doubled by another, that of the Emperor of the Last Days'. This heroic figure was counterbalanced by his evil opposite, Antichrist, who was human but also more than human, destructive but at the same time seductively attractive.
In the thirteenth century a third source of prophecy was added to Revelation and the Sibylline Oracles. Its inventor was Joachim of Fiore, a Calabrian abbot and hermit who experienced a revelation at the end of the twelfth century in which he saw that history took the form of 'an ascent through three successive ages, each of them presided over by one of the Persons of the Trinity'. The Age of the Father and that of the Son had already taken place; the third would be the Age of the Spirit and would be one of love, joy, freedom and the adoration of God.
The influence of this tripartite scheme on subsequent European thought can hardly be exaggerated, Cohn believes; it can be traced right down to the present day. It is clearly there in Marxism and also appeared in Nazism with talk of 'the third Reich' and the 'new order' that was supposed to last for a thousand years; these phrases 'would have had but little emotional significance if the phantasy of a third and most glorious dispensation had not, over the centuries, entered into the common stock of European social mythology'.
The prophets of the Middle Ages appealed mostly to the poor and dispossessed, and they were often set against a background of natural disasters—famine and plague—which people attributed to divine displeasure and sought to mitigate by penance; this was the origin of the flagellant processions of the thirteenth and fourteenth centuries, which figure prominently in this book. The outcome was often bloody revolts against authority and the clergy, widely (and mostly correctly) perceived as corrupt. When these rebellions were put down bloodily, as they usually were, the prophets who inspired them were normally executed by burning.
These prophets generally lacked education. There is however a remarkable exception to this trend, which for me is the most interesting part of the book. This is the heresy of the Free Spirit, which is described in Sections 8 and 9. Far from being uneducated, its proponents included some of the foremost intellects of the time.
The heresy of the Free Spirit has long been regarded as one of the most perplexing and mysterious phenomena in mediaeval history and its nature has been much debated by historians. It has often been suggested that no such movement existed at all outside the polemics of ecclesiastics whose one concern was to defame and discredit every venture in dissent. But these doubts could exist only because no attempt was made to use all the sources available.There appear to be numerous cross-currents connecting this heresy with earlier Christian 'aberrations' and even the Sufis of Muslim Spain, but the most dramatic and important manifestation was that known as the Amaurian heresy, so named for its founder Amaury.
Early in the thirteenth century the doctrine of the Free Spirit was elaborated into an all-embracing theological and philosophical system. This was the work of a most interesting group, consisting of men who had been trained at the greatest school of orthodox theology in Western Christendom, the University of Paris.There were fourteen of these men, all clerics. When their views came to the attention of the authorities, partly through the indiscretion of one of the initiates and also thanks to espionage, they were arrested and questioned. Three recanted and were sentenced to life imprisonment, but the remainder (apart from Amaury, who had died earlier) held out and were burnt, showing no sign of repentance even at the last.
Not much is know about what Amaury actually taught, except that it was a mystical doctrine owing much to neoplatonism. But although Amaury was a professional philosopher the Amaurians were concerned not with intellectual arguments but with inner experience. 'They were convinced that what Christian theology regarded as the unique miracle of the Incarnation was now being repeated in each one of them.'
Indeed they believed that the Incarnation as it had taken place in Christ was now being surpassed [sic]. For these French prophetae had arrived at an interpretation of history which had striking similarities with that of Joachim of Fiore—even though they drew very different conclusions from it.Like Joachim, they believed they were living in the Age of the Holy Spirit, which would last to the end of the world.
That age was to be marked by the last and greatest Incarnation. It was the turn of the Spirit to take flesh and the Amaurians were the first men in whom it had done so—the first 'Spirituals', as they called themselves.Not that this meant a general apotheosis. The world was about to pass through a series of catastrophes in which most of its population would be destroyed, leaving only a 'saving remnant' to taste the joys of divinity.
The Amaurians were believed, probably correctly, to be antinomians, including in their sexual behaviour.
In a Christian civilization, which attached particular value to chastity and regarded sexual intercourse outside marriage as particularly sinful, such antinomianism most commonly took the form of promiscuity on principle.It's easy to see why the orthodox Church condemned the Amaurians. It occurs to me that they would have been quite acceptable in India, where their claims to have achieved divinity would have earned them gurudom rather than the stake.
Towards the end of his life Cohn returned to theme of this book in a wider context, when he wrote Cosmos, Chaos and the World to Come. In fact, his life's work as a historian was largely concerned with how millenarianism and fanaticism have driven the persecution of minorities, especially Jews, in Christian Europe from the earliest times down to our own day.