There is an uncomfortable moment, on entering the first room in the NGS's dauntingly wide-ranging summer exhibition, when Goya's horrific vision, The Disasters of War (1809-14), comes up against David Wilkie's romanticised The Defence of Saragossa (1808).
Against the backdrop of the Peninsular War of 1808-1814, in which British troops came to the aid of Spanish forces and guerillas fighting off a Napoleonic invasion, Goya's mutilated, naked corpses, hacked by a ruthless enemy, clash darkly with the iconic folk heroine - Byron's Spanish Maid' - of Wilkie's heroic painting, as she lights a cannon on the besieged city walls, her husband's body at her feet, in a Renaissance-like swirl of robes.
Goya's shocking images make Wilkie's mythologising set-piece seem woefully inappropriate, even criminal, yet it is in this clash of civilizations, of interpretation and reality, that the fascination of this exhibition lies.
But therein, too, lies the potential danger. The Discovery of Spain, charting the response of 19th and early 20th century British artists and collectors to Spain, is an exhibition of British Romantic appetites, beginning with those visceral Goya etchings, and ending with Picasso's distraught, striated Weeping Woman, emblem of the atrocities of the Spanish Civil War.
By the time we reach the 1930s, the British artists have largely shed Wilkie's Romantic vision of war for the more bluntly nightmarish imaginings of Edward Burra, but the work produced in the intervening period, for a market of stay-at-home Victorians travelling vicariously, could seem tame, stagey, even mediocre, in comparison to Goya and Picasso, not to mention the hall of Spanish Golden Age work - the El Grecos, the Murillos, the Velazquez - which dominates the exhibition, visually.
But this is a collection of interesting subtleties, pieced together from the collections of the National Galleries of Scotland, the National Gallery in London, the Tate, the Stirling Maxwell Collection in Glasgow, the British Museum and a number of other public and private collections.
Yes, John Frederick Lewis' Spanish Fiesta (1836) is a cutesy scene of frolicking Spaniards and castanets. Yes, David Roberts' intricately architectural watercolours are a sort of upmarket Victorian postcard for the discerning traveller, a deliberate, lucrative precursor to his myth-making depictions of the Middle East.
But then there is John Spanish Phillip, whose deep conversion to the artistic inspirations of Spain led to vivid, hugely popular tableaux of Spanishness, such as the emotive La Gloria: A Spanish Wake (1864), that resound with passionate honesty of spirit, if not, perhaps, of subject.
The crux of this exhibition is in the growing fascination with Spain that began as a result of interest aroused by soldiers returning from the Peninsular War. A series of eclectic rooms rigorously chart this trend, from the British collectors' interest in depictions of distinctively Spanish life (The Spanish Picturesque) to their discovery of Spanish Golden Age art; from British artists' fascination with the Islamic South and its light and architecture, to the Cult of Velazquez.
Behind it all, and what seems a long 19th century, is the romance of otherness, of the exoticism that Spain encapsulated, or was made to encapsulate - and still does - for cold-blooded northern Europeans; the pungency of blood in the air, the blinding white sunlight flashing off romantically crumbling buildings, the frisson of the unknown on the Islamic fringes of Europe, a country that was thrillingly alien, but not too alien.
The exhibition resonates with the clash between the vision of Spain that resulted in the likes of Bizet's Carmen - the French, too, were fascinated with the exoticism of their southern, rebellious neighbour - and a fascination with the perceived darkness and realism of Spain's own view of herself, principally as seen, and collected, in the Golden Age paintings of Murillo, Velazquez, Zurbarán and El Greco.
But amidst the more familiar works - many are from our key Scottish collections - such as El Greco's Lady in a Fur Wrap (c.1577-80), the poster image for the exhibition, or the Picassos and the Goyas, there are other discoveries, other connections.
In the room dedicated to Colour and Light, Arthur Melville's wonderfully impressionistic oil, The Contrabandistas (1892), suddenly dominates, its elusive caravan of smugglers winding up an abstract hillside of earthy reds and blues, less Romantic than what has gone before, seeming somehow, unbidden, to take on a retrospective truth, both looking ahead to the Spanish Civil War stories of Hemingway and fighters camped out in the hills, and back to the guerrillas of the Peninsular War.
Not every room in this rigorously thought-out exhibition is wholly successful. The Cult of Velazquez room, whilst containing some compelling works - Sir John Everett Millais' delightful Souvenir of Velasquez (1868), John Singer Sargeant's luminous, telling portrait of W. Graham Robertson (1894), John Phillip's homage to Velazquez' Las Meninas as testament to his own intense fascination with Spain and her artists - lacks the focus that, arguably, a prominent Velazquez, the inspiration for it all, might have created.
The collection itself is impressive, although there will be those for whom the bombast of the Spanish Golden Age detracts from the less intense visions of the Victorian cultural documenters. The walls of the RSA are painted to suit the works in each room, from a russet red in the Goya room, to the deep purple of the central Spanish Golden Age hall, to a somewhat custardy yellow, presumably meant to evoke the baked earth of the south, backing the architectural illustrations of the Alhambra in A Dream of the South'. But whilst the works are neatly, thoughtfully corralled into their respective rooms, the strands are almost too disparate, leaving a sense that, in some areas, coverage is too thin.
And then, of course, there is that cumbersome title, with its rather woolly, all-things-to-all-men implications. It might almost have been better not to mention Goya or Picasso - it sets up an unnecessary expectation which is not fulfilled - but subtitling the exhibition From Wilkie to Burra' would not have quite the same allure. It does a disservice to an often impressive exhibition that rigorously charts a compelling fascination. The exhibition runs until October 11 at the National Galleries of Scotland, The Mound, Edinburgh. Tel: 0131 624 6200. Tickets, £8 adult, £6 concession, free to children under 12.
