Occasionally a book appears which is so distinctive in character that it defies orderly categorisation. Such is certainly the case with Christopher Woodward's work, a delight to read but a devil to describe. It is, more than anything else, an intensely personal meditation on the nature of ruins and, as the author himself explains, an opportunity to show what an inspiration they "have been in earlier centuries". But his chapters follow neither a chronological nor thematic pattern and Woodward moves fearlessly from one country and one era to the next within the space of a page.
Nevertheless, almost despite himself, certain leitmotifs gradually make their presence felt. It becomes clear fairly soon, for example, that Rome is Woodward's favourite city, perhaps because - as he tells us more than once - it is the birthplace of his wife; the text closes with a photograph of the author and his new bride standing together on the Campidoglio.
Another favourite subject is the "damage", for want of a better word, done to ruins by well-intentioned archaeologists and administrators who remove undergrowth, erect neat fences, insist visitors walk along designated paths and bring order to what Woodward believes would have been better left disorderly.
He describes the impact which the Baths of Caracalla made on Shelley when the poet passed through Rome in 1818 before proposing readers visit the same, thoroughly restored, spot today, "and I defy you not to be saddened - and then angered - by the bathos of the scene now".
Actually, as he acknowledges, the turning-point for the Italian capital came with the unification of the country in 1870; before that date, Rome had been left to moulder for centuries and the Baths of Caracalla, Shelley's "thick entangled wilderness of myrtle and bay and the flowering laurustinus" were thought "one of the most beautiful spots in the world", according to Augustus Hare, a much under-appreciated 19th-century writer quoted more than once by Woodward. But even within Hare's own lifetime, the baths had been so transformed through restoration that, in his opinion, they had become "scarcely more attractive than the ruins of a London warehouse". It soon becomes apparent that Woodward is a Romantic of the early 19th-century variety, his heroes being writers of that period such as Chateaubriand and Shelley, who responded with emotional intuition to derelict buildings. He argues that every ruin possesses two characteristics: "It has an objective value as an assemblage of brick and stone, and it has a subjective value as an inspiration to artists."
There can be no doubt that he finds the second of these values the greater. For this reason, any attempt to clean or tidy structures which have fallen into decay will destroy their ability to inspire.
"No ruin can be suggestive to a visitor's imagination," Woodward suggests, "unless its dialogue with the forces of Nature is visibly alive and dynamic." He delights in the overgrown medieval city of Ninfa in southern Italy, but loathes the Colosseum, here dismissed as "a bald, dead and bare circle of stones".
What distinguishes him from the Romantics is his disinclination to draw any philosophical conclusions from the spectacle of a ruined building. Woodward is not troubled by intimations of mortality and although, naturally enough, he cannot resist quoting from Ozymandias ("Round the decay/Of that colossal wreck, boundless and bare/The lone and level sands stretch far away"), this does not lead to any presumption that all great monuments must eventually crumble.
The latter belief appears to have been most commonly held among writers who disliked their own age and sought relief in the assurance that ruination must be the inevitable fate of a hated environment. Woodward notes that it was the 18th-century author and painter, John Dyer, who first suggested that "a building can seem more beautiful in ruins than when its original design is intact". But he does not draw the most obvious conclusion from this argument: that ruins are admired because they allow the spectator to project onto them an idiosyncratic interpretation of the past.
Actually, despite the presentation of a dazzling variety of opinions on the subject of ruins over the past two millennia, conclusions of any kind are absent from the book. Woodward's primary intention seems simply to share the delight he finds in ruination with his readers. This he manages to do with a singularly winning charm.
Robert O'Byrne is an author and an Irish Times journalist