Whales have supplied a bewildering array of human needs. As recently as the 1960s, whale oil went into ice cream, soap, brake fluid, linoleum and margarine; whale livers were turned into vitamin A; whale ink was used to dye typewriter ribbons; tennis rackets were strung with whales' insides and cat food was made from whale meat. In earlier times, during the 19th century, whales provided us with whalebone corsets for pushing ladies' bosoms into unnatural forms, with lamp oil to light houses, with the pungent perfume of ambergris for anointing monarchs or seducing lovers, and with whale ivory - the teeth - for piano keys. Now, since the international moratorium on whaling of 1986, most of this giant whale economy has collapsed. Soya beans, plastics and various mineral oils have easily taken their place. But we still exploit whales for at least one thing: myth-making.

Ever since Jonah found himself stuck in the belly of one for three days and three nights, whales have been an epic spur to the human imagination. Philip Hoare has been in awe of these floating beasts since he first saw a killer whale at Windsor Safari Park as a child in the 1970s. Now a 50-year old writer (the biographer of Noël Coward), Hoare counterbalances his life in a treeless London tower block with dreams of whales - of finbacks, humpbacks, blue whales, minkes but most of all of the sperm whale, this “emperor of whales”. It is the sperm whale, as Hoare writes, that children draw when asked to draw whales, and it was the sperm whale that crazed Captain Ahab pursued in Moby-Dick. The name is a misnomer. The sperm whale's head is actually filled with a “waxy oil” - ‘Such a softener! Such a delicious mollifier!' wrote Herman Melville - which got mistaken for, ahem, another cloudy substance. The idea that the whale carried sperm inside his head was just one more sign of his impossible majesty.

Hoare is chiefly concerned with the relation between humans and whales. As mammals are composed largely of water, we are technically close to them, but in practically every other sense they are a world away from us. “Whales exist beyond the normal,” says Hoare. Until a few generations ago, with the advent of underwater photography, the life of whales and their extremely complex social arrangements were a mystery. So we blithely built stories about the animal that Milton called “that sea beast Leviathan”. During the age of whaling when men hunted them with harpoons, whales came to symbolise both “wealth and power” and “death and disaster”. Now, with right-on CDs of whale song and Greenpeace campaigns against Japanese whale meat, they symbolise a kind of fuzzy eco goodness. Hoare is not immune to the myth-making. When he gets hit with spume from a finback, he feels he has been baptised. Nor does he condemn the tendency to romanticise whales. “While it is a mistake to anthropomorphise animals merely because they are big or small or cute or clever, it is only human to do so, because we are only human, and they are not.”

At several moments, Hoare allows himself to go beyond anthropomorphising and to speculate what the whales think of us, their hunters. “If sperm whales have religion, do they believe in us?” When he finally encounters whales first-hand, underwater in the Atlantic, he senses that they “had the measure of me; that they knew what I was, even if I could not comprehend them; that I was an object in a four-dimensional map, appraised in six senses”.

This is a WG S bald-ish narrative, in which thoughts about history and literature (above all, Melville) combine haphazardly with Hoare's inner life (the death of his mother, his horror of public swimming pools) and his journeyings around the world, from Nantucket (home of Moby-Dick) to Hull (home of a whale museum). This rambling form is studded with generous illustrations and poetic details. In Hoare's hands, whales are almost limitlessly strange and interesting. We learn that blubber does not feel flabby after all, but hard, “more like wood than fat”. There is a terrific section on ambergris, a rare kind of hardened whale faeces that occurs occasionally when the sperm whale has swallowed squids' beaks. Despite its disgusting origins ambergris has for centuries been a key component in the manufacture of perfume and is still one of the ingredients in Dioressence by Dior. A single lump of ambergris can sell for thousands.

The problem is not the concrete details but the flights of fancy. Hoare seems so carried away with his subject that he goes metaphor-crazy. Whales, we are told, are “giant, living jigsaw puzzles”, but they are also “clouds”, “countries in their own right, planetary communities”, “granite” and “gentle giants” to name but a few of the images with which Hoare's prose teems.The hugeness of his subject seems to have encouraged him into portentous overstatement. “It is the whale's fate to share man's air, and so risk its life in the process of sustaining it, caught in a bind as much as any philosopher perplexed by the human condition.” You might say the same of mice. Hoare tells us that “Moby-Dick surpasses all other books because it is utterly unlike any other.” Would he say as much if he wasn't himself writing a book about whales?

Having said that, Leviathan perhaps functions best as a companion to, and exhortation to read, Moby-Dick. After fearing its heft for years, I was stunned to discover what rich humour - as well as epic madness - Melville extracts from the whale. Unlike Hoare, Melville never forgets that whales are absurd beasts as well as great ones. He dismissed his own masterpiece with the line “blubber is blubber”.

If the real thing seems too daunting, however, I recommend starting with a brilliant graphic-novel pop-up version that came out last year. It is by Sam Ita, a disciple of Robert Sabuda and re-creates Ishmael, Queequeg, Ahab and the white whale in stunning 3-D illustrations reminiscent of Hokusai waves. The fact that whales can raise even the humble pop-up book to such greatness bolsters Hoare's thesis. Whales might be better off without us; but we and our art would be poorer without them.

Leviathan: Or, the Whale by Philip Hoare
Fourth Estate Offer price £17.09 rrp £18.99, to buy click here.

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