The upright canvas, some 4’6’’ by 3’, stood on Salvator Rosa’s easel, prepared with a burnt umber ground. The painter first attacked it, as far as I can see, with a black-loaded brush, dragging a jagged stuttery line almost from top to bottom. That was to be the rock edge of Etna’s crater. Where the volcanic glow was to fall, Rosa slapped on a queasy mid-tone mix of sienna and smalt blue; capped it with brisk blurts of white; later, knocked the resulting rock planes back into readable order with red and yellow glazes. But that vertical divide of his, tumbling and forking in ever crazier lurches, still retains a lightning urgency. Here you meet the gestural painting of the 1660s, as vehement and imperious in its own way as the art of Clyfford Still.

There are not all that many ways in which you could call Rosa’s brushwork graceful. Slackening in pace as he dabbed in some clouds beyond the crater, it snarls up awkwardly over the canvas’s lone figure – that of the philosopher Empedocles, who is seen hurling himself, for some reason or other, from an inner ledge into the gulf of fire below. In fact one of the first things I noticed, as I went round the recent exhibition of Rosa’s work at Dulwich, was the painter’s own moth-to-the-flame impulse to tackle types of figure painting that lay beyond his grasp. Yes, he can sketch the heroic poses that were the stock-in-trade of 17th-century Roman history painting, but when it comes to modelling them in oils, the bodies turn vegetal – tubular, globular. There is no inner tension and the highlights never seem to hit home. The touch is just as vague when he turns out the kind of edifying head-study supposed to add gravitas to a salone: the frowning Stoic, the scowling Cynic, the po-faced female allegory. He relies on a very small repertory of hand movements, just as his pigment-shopping never ventures beyond the cheap materials expended on the Empedocles canvas. There are the skittering light-streaks that activate valleys and skies in his narrative landscapes: the lush, fat cupping strokes that conjure up cloudbanks; their diminutive echoes in the leaf-curls painted on afterwards; but principally, underlying all these, the executive and angular hack that hands the canvas its structure of rocks and tree boughs.

‘The Death of Empedocles’ by Salvator Rosa

That is his forte and the reason he stayed in other painters’ minds. For Rosa, nature proceeds from his right shoulder: the geological is the gestural. He is remembered as a progenitor of a taste for ‘the sublime’ partly because he went out looking. Writing in 1662 about a journey through the Apennines, he paraded a saturnine temperament finding its objective correlative in the ‘terrifying beauty’ of ‘a river hurling itself off a precipice’ and in ‘those utterly desolate hermitages which we could spot from the road – how many times I longed for them, how many times I cried out for them!’ But all that became memorable painting only because the same inner yearning drove Rosa to commit major graphic decisions directly to canvas. The life of his Landscapes with Hermits, with their lungeing, crashing diagonals, or of other stand-outs in the Dulwich exhibition (e.g. Jacob’s Dream, a galumphing six-footer from Chatsworth), is fairly close to the life of his pen drawings. Turn to those, and his jittery, stab-and-thrash efforts to summon up figure compositions become irresistible in their sheer unselfconscious urgency. They would have spoken for him better than the attempt to represent the broad range of his works on canvas, from his genre lines in philosophers and banditti to his grandiose but gormless satires.

Rosa’s ambitions were wide, his gifts narrow. (In the permanent collection at Dulwich you meet people whose territory he tried to step on, such as Claude or Guido Reni; before them, his efforts fall apart.) The curators might nonetheless argue that the disparity is entertaining. The man described in Helen Langdon’s catalogue essay – and, more fully, in Jonathan Scott’s 1995 biography – is loud, deplorable, disarming. Before settling in Rome in 1649 at the age of 34, Rosa had trained in his native Naples and had passed a charmed nine years in and around Florence. That one-time hub of artistic innovation had, under a Medici autocracy, become inward-looking and genteel, a decorous playground for banter, versification and am-dram. Rosa, always ready with a quip and a rime, thrived in such a milieu, amusing his circle by working up novelty hokum such as the witchcraft paintings shown at Dulwich. But the scene was unchallenging. He packed his bags, rented a house on the via Sistina and sized himself up against Poussin – the last word, in mid-century Rome, when it came to easel painting with intellectual credibility.

Paint serious, paint big! An 11-foot-tall Democritus in Meditation (presently in Copenhagen) was unveiled, littered with skulls, moonstruck clouds and carefully researched antique curios. Ricciardi, the writer friend who had supplied the erudition, was plugged for further themes: ‘Now that Rome has discovered that I am highly original in my ideas, I must live up to expectations.’ Rosa also sent Ricciardi a philosophic self-portrait – the poseur in cavalier ringlets contemplating a skull, as if Russell Brand were to land the role of Hamlet. But composure was not Rosa’s métier. He took fright when the Chigi, butts of his satire, took over the papacy in 1655, sent his mistress and their son out of town, then cursed his own cowardice: ‘Am I the person who let himself believe that he was the foremost man of the century? Of the finest talent, of unique wisdom, of the most proved discretion? For shame! I am a simpleton, an ass, a blockhead.’ Worse followed: the boy died of the plague; and his siblings had all been packed off at birth to the foundling hospital, Rosa insisting he couldn’t afford them.

But as Blake wrote, ‘If the fool would persist in his folly, he would become wise.’ The Death of Empedocles was just one in a succession of foreboding, thunderous histories that occupied Rosa over the following dozen years. By 1668 they had bludgeoned a kind of pre-eminence for him, so that he was deemed the sole living master whose works might hang alongside those of Veronese, painting a century earlier. The pictures’ themes were for the most part deliberately unfamiliar and recondite. Why, you might wonder, did Rosa paint a philosopher diving into a volcano? Arguably, he could have seen something Faustian there, a seeker after knowledge issuing a dare to mortality – something to resonate while the memories of Giordano Bruno and Galileo still lingered. But Rosa’s own letters are not particularly free-thinking in their drift. (No more are they particularly devout.) As I see it, the image is chiefly one of fellow-feeling. The plunge is what the showman takes. There’s a brink and the audience – the great unknown – lies beyond it: get up there, throw in all you’ve got, court disaster if you must, but whatever you do, make something happen!

Rosa, more than any painter before him, came to live for the exhibition. ‘I have risked everything to achieve fame,’ he told Ricciardi as he pitched his powers against Veronese’s – a climax to two decades in which his year had pivoted on Rome’s big March exhibition, held at the Pantheon, and its August one, at San Giovanni Decollato. Xavier Salomon, in a catalogue essay about these artist-organised events, describes Rosa reaching ‘a level of panic, over-working and exhaustion every summer, in the Roman heat’, as he prepared for the August show: ‘My nature is subject to these bursts of enthusiasm and heats up with tight deadlines,’ he wrote to Ricciardi. His latest ‘most original’ subject, bursting with its ‘extraordinary novelty’, would be kept under wraps – ‘what is important is that up until now no one has seen it’ – until its blaze of sudden glory: ‘I electrified Rome to a degree that you could not even understand.’ Then followed fame’s concomitant, Envy, whom he addressed in verse: ‘You, who never further/than only a step have been away from me at the Pantheon’. (It seems that Rosa’s poetry reads not much better in the original Italian.)

Here then is a protagonist who summons up, through his own vivid cantankerous presence, an early form of modern art culture. That’s to say, a scene that revolves around goods to hawk, strong personalities (Rosa’s letters constantly brandish his own ‘eccentric genius’) and public fora, rather than around site-specific works (frescoes, for example) linked to rooted systems of iconography and patronage. Of course these two styles of operation could coexist. The Rome inhabited by Rosa was also home to Pietro da Cortona, a master-decorator of palaces much as Veronese had been back in the 16th century. Yet there’s a sequential order. In Veronese’s Venice, exhibitions weren’t yet a feature of the scene: if we think about Rosa, we enter a new cultural zone, one that subsequently would be occupied by David, Delacroix and Courbet. His San Giovanni Decollato was a forerunner of the salons of those equally proud, shouty showmen.

That’s a handle you might think historians would grab at when they’re discussing the way modern art got going. But there are reasons why they’ve left off. First, 17th-century Rome lacked art journalism of any kind, let alone an equivalent to Diderot or Baudelaire. It had its biographers and theorists – notably Giovan Pietro Bellori, the Vasari of the Seicento – but if we seek its day-to-day hubbub, the one hand we hear clapping is Rosa’s. Second, the Roman scene would soon become a sideshow as Paris came to dominate the world of European art. After Poussin, the loftiest of the city’s easel painters, died in 1665, the French would treat his legacy (and that of Claude, his fellow expat) as their own national property. And by 1680, when the long career of Bernini, Rome’s multimedia cultural supremo, came to an end, the appetite of the city’s churchmen and grandees for patronising new art had been well nigh exhausted: from then on the local cultural economy increasingly revolved around foreign tourists and students.

So much about the Rome in which Empedocles was painted belongs to some far-off historical frame, above all the Catholic triumphalism manifested in Bernini’s colonnades for St Peter’s piazza or in the impeccably prim altarpieces of Carlo Maratta, the president of the Accademia di San Luca. And so little moved forward in the fractured Italy of those days. Rich families vied for the papacy; loyalties inclined to this or that superpower, to France or to Spain; momentarily, the people of Naples rose against Spain and were suppressed; every two or three decades, a plague would descend. The economy was an ox-cart stuck on a muddy road, with most cities’ populations lower in 1700 than they had been in 1600. The church’s condemnation of Galileo in 1633 was a symptomatically dismal episode in the life of the mind. Wherever else it may apply, the historian’s ‘crisis of the 17th century’ seems hardly the right phrase here. Shall we say, then, that Rosa got things right first time: that in his style of artistic operation, he truly was ahead of his time?

But surely there’s some glitch in our thinking here. These days everyone’s pet example of an art that feels ‘modern’ issues from Rome to be sure, but from two generations earlier. We have, that is, a sense that Caravaggio is a modern-art phenomenon (a bad boy, a hardnut) making a modern-art-style move when he astonishes the city with his new realist altarpieces in 1600. After Caravaggio comes to a mythically appropriate bad end ten years later – a desperate fugitive on a desolate coast – we have little further use for the designation ‘modern art’ till we reach Paris well over a century later – in the time of the Revolution, perhaps. The passing interlude of Rosa’s career merely throws into relief some distant and alien era we vaguely label Baroque. How can that be historically coherent? There ought to be sounder co-ordinates with which to chart the transitions in question than those derived from the Great Man principle (‘Then a prophetic genius arose; then there was a gap, till the next genius’). Or are those all we need, in fact, if we happen to be writing the history of art?

Three recent books bear on these issues. The Seicento specialists Richard Spear and Philip Sohm have put together Painting for Profit: The Economic Lives of 17th-Century Italian Painters, which explores what new co-ordinates one current academic strategy has to deliver; while two treatments of Caravaggio, by Andrew Graham-Dixon and by Michael Fried, come at that painter’s place in history from wildly disparate angles. Spear, Sohm and their five coauthors investigate five 17th-century urban art worlds. Those of Florence and Venice are so downbeat they would be the despair of most inquirers, so patently were both cities skulking in the shadow of former Renaissance glories. More enticing are Bologna and Naples, the two city schools that gained international profiles during the Seicento. The rationalism of the Carracci, Reni’s elegance and Guercino’s warm piety all contributed to Bologna’s reputation, which rose when those artists went on to Rome; whereas Naples – even then a frantically crowded urban jungle – was a base for the era’s jangliest, most confrontational painters, such as Jusepe de Ribera and Artemisia Gentileschi: a development in fact prompted by Caravaggio’s arrival there in 1606, fleeing Rome after he had murdered Ranuccio Tomassoni.

Rome, then, remains the key to the story. The one Italian city to buck the trend and expand (since cardinals chose to splash out there, on tithes offered up in Manila or Lodz), it was the destination for all art’s pilgrims and contenders. It looked the most promising venue whether you had free-standing pictures to sell or wanted to do frescoes; somewhere in between, there was the hope of landing an altarpiece commission. Thus it was that in 1601 Caravaggio and Annibale Carracci faced one another down with adjacent canvases in a single chapel at Santa Maria del Popolo: here, glare and blackness, pain and plebeian flesh; there, classical draperies, exalted sentiments and rich-glazed colours. Carracci alumni, taught to draw and draw and draw, proved well positioned to bag plenty of site-specific jobs, while the Caravaggists, who went straight at the canvas with their paintbrushes, became all the rage in the picture market.

By 1630, however, the latter had suffered the usual fate of fashions, and the gravely intellectual Poussin – famous for declaring that Caravaggio had set out ‘to destroy painting’ – was emerging as the arbiter of easel-painting values. His party had new adversaries to face. They had a distaste for grandiose decorators such as Cortona who were too profligate (too ‘Baroque’, we’d now say) in their pictorial means, but truly detested a fresh vogue for the plebeian that was sweeping the market. A gang headed by Dutch expats, the ‘Bamboccianti’, were ‘depicting rogues and poverty,/And porters, urchins and pickpockets,/Vineyards, wagons, limekilns and taverns …/One who pisses, one who shits.’ The tut-tutting here is Rosa’s, who, come 1650, wanted to be thought as serious as Poussin, though in fact his witch and banditti-numbers reflected the same business logic, the same urge to develop new product lines. From the mid-century onwards, however, there was at least a consensus that the plebeian ought to be marginalised. Increasingly, a hegemony of the decorous set in, a sweet-scented rationalism-lite served up in the Accademia by Maratta and his theorist friend Bellori.

Painting for Profit looks past the ideologies and rhetorics involved in these style wars to examine the interests at play. The title points us towards a world of rational self-interested agents: maybe if we look at the high achievers among them, common patterns will emerge. For instance, Reni’s art, with its beauteous physiques and silvery suavity, has a very different profile from Rosa’s, yet his was a pricing strategy Rosa would have recognised and saluted: occasional stroppy ‘Because I’m worth it’ grandstanding, plus regular ‘Oh, up to you!’ guessing games for clients desperate not to make fools of themselves before a great master. It did the trick, even if Reni did keep blowing his mega-scudi earnings at the gaming tables. And by the same token Reni scorned softheads like Guercino, who charged for canvases on a straight figure by figure rate. Artisan practice, letting down the profession: hopelessly pre-modern!

The book aims to bring the low achievers into the picture too. You glimpse in passing Onofrio de Anfora, a murdered Neapolitan whose workshop inventory reveals scores of saints’ heads turned out at ‘a semi-industrial rate of efficiency’, and the Venetian landscapist Bartolomeo Pedon, who, ‘“reduced to working for shopkeepers”, walked around barefoot with only a tattered cloak and sword to cover his naked body.’ A ragged kind of profession, in truth, painting: ‘The gap between poor and rich,’ Sohm reports, ‘and the uncertainty of regular employment, resemble the income inequality and working conditions of Venice’s courtesans more than its master craftsmen, teachers or bureaucrats.’ While Spear notes that in Rome, membership of the Accademia, instituted in 1593 to promote the art of painting, might hardly be worth the sub, being ‘no guarantee of public advancement and financial success’.

These are salient details poking out from a towering stack of evidence. Seventeenth-century Italy was so literate, so aboundingly bureaucratic: the authors have a great deal to sift. I enjoyed, up to a point, overhearing so many painters whinge. (Artemisia wriggles after underpricing a Diana and Actaeon, a commission involving eight differing nudes: ‘The expenses are intolerable, because out of the 50 women who undress themselves, there is scarcely one good one.’) But for a sharp and witty impression of their lives in those days, Patrizia Cavazzini’s 2008 study, Painting as Business in Early 17th-Century Rome, offers better value.

All those involved in Painting for Profit are impressive and eloquent scholars, but I don’t see that their compendious report offers a clear answer to the question Philip Sohm started with: what might be the purpose of an economic history of art? If anything, the book is too modest in its conclusions, too ready to concede their provisional status. At one point Sohm mentions the art historian Michael Baxandall. Anyone who reads his Painting and Experience in 15th-Century Italy (1972), with its ground-breaking focus on what people were trained to have an eye for during that period, will go back to Quattrocento art and notice new things, facets otherwise invisible. That hardly happens here. (Well, we are told why sometimes there are gaps in Guercinos where figures might have stood: the client ceased paying.) Yet, as Spear and Goldthwaite mention, in the 1980s an economic historian, John Michael Montias, reset the questions for Holland’s art history when he analysed the 17th-century growth of its picture market in terms of product innovation (new lines of subject matter, whether they be ‘limekilns and taverns’ or banditti) and of process innovation – i.e. finding ways to paint faster and cheaper.

I wonder if you couldn’t twist those two can-openers into the Italian art scene rather more incisively – particularly the latter. A Rosa, to my eyes, looks a rush job compared to a Claude. Caravaggio, 50 years earlier, was known for drawing and painting straight from the model: that certainly was the way his followers read the sudden, in-your-face glare of his work. The greatest Guercinos, those from the 1620s, also ride a period ethos of celerity – dazzling lights flash by, the brush races as the heart races. And towards the century’s end, we see the rise of the super-slick all-rounder, Luca ‘fa presto’ Giordano, Mr Do-It-Quick. If we could have peered into their studios, would all these operators have looked so efficient? We can’t know. We could, however, trace the way that ‘process innovation’ became a defining issue among painters: the impulse to accelerate, to continually seek out new pictorial forms, provoking creative counterreactions from those such as Poussin.

Painting may have been getting quicker, but was it getting better? Far from it, in the view of contemporary Venetian commentators. What room for manoeuvre was there now left, in the wake of Bellini, Titian, Veronese and Tintoretto? No doubt similar grumbles could have been heard in Rome too. A foundational tenet for all adherents to rationalism, from the Carracci to Maratta, was that God – i.e. Raphael – had departed this world in 1520. Painters who failed to look up and back in his direction – the Caravaggist brat-pack, the lavatorial Bamboccianti – were merely symptoms of a degenerate age. Many viewers nowadays would fall in with that negative estimate of the Seicento, but for opposite reasons. The rationalist or ‘classicist’ repair project bores and alienates them – and there’s a political tinge to that dismissal, since classicists get regarded, rightly or wrongly, as artists bedding down with an absolutism that was tightening its grip. Whereas those who plumped for plebeian subject matter and slam-it-down technique are seen as representing an innovatory, modern-art ethos that an ever more stagnating Italy would marginalise.

Andrew Graham-Dixon’s Caravaggio enlarges on this scenario. Graham-Dixon offers no special insights into the painter’s techniques – he hardly pokes his nose inside the studio – but has plenty to say about his imagery. His Caravaggio is a radical original in this sense: he doesn’t bother looking at the other painters of his day. Rather, he listens hard and reads hard. Growing up in Milan, he was impressed by the Counter-Reformation earnestness of the ministry of Archbishop Carlo Borromeo. Then, making his way through the Rome of the 1590s with his pictures of cardsharps, pretty boys and fruit, he was taken under the wing of a cardinal whose sympathies interlocked with Borromeo’s: a concern for the poor was a leading accent of their Catholicism. During the six-year run of Roman altarpiece-painting that began in 1600, Graham-Dixon argues, Caravaggio consistently chose to treat his themes in this ‘pauperist’ spirit. The rough faces, dirty feet and ragged clothes described by his terse brush placed him on the ‘left’ of a debate about how to handle early modern Italy’s surging, immiserated masses.

The left would lose that debate: pauperism fell out of fashion, with the church deciding in Graham-Dixon’s words, that ‘the poor were there to be controlled, regulated, put in their place’ by an art that would ‘awe, daunt and stupefy them’. There could be ‘no place in this new Baroque sensibility for an artist such as Caravaggio’. Politically, then, he was a progressive on the defensive. But what can have shaped the unfamiliar visual sensibility he brought to Rome? The influences Graham-Dixon opts for are the sacri monti of Caravaggio’s native northern Italy, lurid, life-size tableaux of the Passion story conceived in the late Middle Ages:

The very idea of looking back, past the etiolated late Mannerism of his day, past the art of the High Renaissance, to vivid and robust traditions of popular religious sculpture … was a profoundly original move. It ran directly counter to the prevailing aesthetic orthodoxy of late Renaissance thought, as expressed by Giorgio Vasari in his Lives of the Artists – namely, the belief that art should continually evolve and progress.

Graham-Dixon’s Caravaggio stands on a peak alone, gazing into the medieval past and casting a long shadow into the modern-art future: the Great Man theory stands vindicated. It’s an account that involves some drastic disjunctures – as Graham-Dixon acknowledges in subtitling the book A Life Sacred and Profane. For most of the records of that life come from the Roman police, who knew the radical genius all too well: he was that edgy, uppity thug you avoided if he was heading down your street, and they wouldn’t have been the slightest surprised when he fled town having run a sword through Ranuccio Tomassoni. This duality of Caravaggio’s persona is ably handled by Graham-Dixon. He tells his story excellently, with a genial old-fashioned courtesy to the historically curious lay reader. He enjoys detective work and has a persuasive hunch that the fatal duel was some form of turf war: that Caravaggio, just like his victim, was a pimp, running girls who could double up as models, and who one or the other was trying to poach. (Caravaggio’s concurrent taste for boys gets relatively downplayed.) The frantic last four years – the painter on the run hurtling through Naples, Malta, Sicily and then Naples again, to die alone at last in a Tuscan fishing village, having missed the boat that would take him back to Rome and a pardon – are told at a brisk crack, and more accurately than ever before. Remarkably, during the decade since the last two biographies of this ever saleable subject, researchers have uncovered fresh facts, and Graham-Dixon pieces these together with further reasoning of his own.

So many biographies: having also enjoyed those previous two (by Helen Langdon, the doyenne of Seicento studies, and by a provocative Peter Robb), I find that my image of Caravaggio turns increasingly – well, ‘synoptic’ would sound handsome, but ‘blurry’ might be more apropos. It would help to have clear lines defining where his oeuvre starts and stops, but after 400 years they are hard to draw. I notice that the canvas reproduced on the dustjacket of Michael Fried’s The Moment of Caravaggio is a Crowning withThorns ignored by Graham-Dixon, who evidently rejects its authenticity. My own insignificant hunch is to side with Graham-Dixon here, but that doesn’t affect the fascination with which I read Fried’s lecture series. Let’s settle for ‘blurry’: even if one of the Caravaggisti was at work in this case, they remain the most stimulating bunch of blatant imitators you could ever investigate, and besides, Fried brings some of them into his argument.

It’s an argument that’s difficult to précis, Fried claims, since ‘the issues that animate these lectures are too difficult or perhaps simply too obscure.’ Fried is one of the great auteurs of art history. Like the films of Fellini or Almodóvar, his books have a strong brand identity: whatever he discusses, you always know you are in a certain special zone, a Friedland. And that is partly because your guide keeps offering you the exit. My thoughts, he avows, ‘are bound to strike many readers as going far beyond the bounds of legitimate art-historical interpretation’. Those readers may well regard ‘the account I have just put forward as an interpretive fantasy’. Or might they give that account more credence if they plunged in deeper? He reminds them that in a trilogy begun in 1980, he approached French painting from Greuze to Manet in terms of an overarching project ‘which eventually, more than a hundred years after it got under way, reached a critical stage’. His analysis of Caravaggio will, he hopes, take this already long view a stage deeper into the past.

He addresses the question of the co-ordinates that relate painting circa 1600 to what eventually became modern art proper. He finds some of them in the conditions of display. From his early cardsharps and pretty boys onwards, Caravaggio was developing the possibilities of what Fried terms ‘the gallery picture’: not exactly an item for open exhibition, but one to hang in a patron’s collection among other painters’ work, competing for attention. In such a competition, Caravaggio’s pictures sought to draw viewers more powerfully in, both by depicting figures who were themselves deeply caught up in their own mental states, and by doing so with an equivalently rapt descriptive care. Starting with his work of the 1590s, then, ‘absorption’ and realism – the themes that Fried loves to trace through subsequent phases of art history – arrive together as a mutually supportive pairing.

Yet Caravaggio’s picture was bound to issue from the studio as a detachable commodity: he himself must draw away from it; must, as Fried puts it, ‘recoil’. The painter had to alternate: one moment he would be deep in there, the next he would be staring from the outside. Fried argues that Caravaggio’s pictures symbolise this tension, which is intrinsic to their production, on several levels – above all, in their interest in decapitation. (Think of the ever compelling David in Rome’s Galleria Borghese, the boy dangling a Goliath head, which is the painter’s own, from his left hand.) The violence that permeates his oeuvre indirectly expresses ‘the severing or cutting out of the painting from its immediate environment as well as, at the limit of possibility, from the painter himself. At any rate, this will be my claim.’

I appreciate the offer of an exit, having little faith that these later parts of Fried’s argument correspond to anything that ever went on in anyone’s mind except his own. This scheme of symbolisation seems insufficiently motivated: we are asked to believe that a palpable, content-rich chunk of experience, the pictured violence, is an epiphenomenon, a pointer to another form of experience that is intrinsically peripheral and elusive. Common sense suggests rather that Caravaggio the painter of violence is thoroughly bound up with Caravaggio the perpetrator of violence, the filler-up of police files. Fried also leads his readers into his hypotheses via a desperately tenuous analysis of the history of self-portraiture. Here, as in his other books, his observations on works of art rarely come across as the necessary conclusions to which all the evidence points.

And yet they become unignorable observations, as you return from his text to the art, permeating all your looking. If he is wrong, his errors are so much more interesting than the ascertainable facts: which is to say that you are in the presence of a great creative imagination. Moreover, while Fried forever cleaves to a personal vocabulary, centred on his term ‘absorption’, he is no blinkered dogmatist. His thought wells up from a huge, inexhaustible love of gallery-going. The curiosity about the whole European tradition demonstrated in his choice of illustrations – which extends to many an overlooked Seicento original, such as Giovanni Serodine – rather puts to shame Graham-Dixon’s tactical spotlighting of an isolated Caravaggio and pat periodising dismissal of the art that would follow after.

To narrate art history it’s convenient to periodise, and to make it vivid it’s convenient to moralise. Instinctually, we tend to unite the operations, thinking for instance of the Baroque as bad and the modernising as good, or maybe vice versa. The instinct makes sense to the extent that art is a social communication which may have concrete effects on people’s lives. Fried writes in awareness of all this, but with a sense that in European painting, at least, the crucial effects occur on an intimately psychological rather than a broad social level; and so, if you are seeking a moralised narrative, it has to be some form of psycho-history. Anything less would be facile. In their uniquely anxious and driven way, his inquiries do keep rooting away for the truths of human experience that might inform moral judgments. Like Graham-Dixon with his focus on pauperism, he is possessed by the suffering he sees in Caravaggio. Gazing at the canvas whose authenticity Graham-Dixon disputes, he worries whether he’s getting too carried away, too absorbed: ‘I can scarcely claim to know with certainty that the Crowning truly portrays Christ’s state of mind as he underwent his torments.’ And then, in one of the book’s most learned and also most moving passages, he connects that doubt of his to the tragic doubts of Lear, Othello and Hamlet, and – beyond the world of art – to ‘the necessary separateness of persons and their consequent opacity to one another’. Rosa, too, knew about absorption and opacity. In his rant against the painters of poverty, the Bamboccianti, he aimed his sharpest lines at their patrons, the art connoisseurs: ‘The living beggars, wretched and bare/don’t receive a single penny from those who/splash their scudi on the painted version./Those whom in life they abhor, in paint they adore.’