Timothy's Book, by Verlyn Klinkenborg

Never act with animals or children, runs the old acting advice. And never write in their voices, authors of books for grown-ups should add. That way, normally, lies toe-curling whimsy and stomach-churning "charm". So the prospect of an experienced American writer and editor (on the board of The New York Times, no less) penning a memoir in the character of a tortoise owned in the 1780s by the Hampshire curate and naturalist Gilbert White sounds about as alluring as a tartan overcoat on a Park Avenue pooch. Against many kinds of odds, Timothy's Book seduces and succeeds.

It does so in large part thanks to White himself. His own observations nourish this transplanted reptile's report from an alien land, a "cold, manicured country" plagued with too many people after the sun-baked solitude of Timothy's home on the Mediterranean coast of Turkey. Inevitably, Verlyn Klinkenborg draws page by page on the loving detail of crops and customs, wildlife and weather, that make White's Natural History of Selborne (1789) such a fashion-proof delight. Through drought and flood, snowstorm and heatwave, chalk-digging and hop-picking, the tortoise (a misnamed female) brings White's bustling backwater to radiant new life.

Yet Klinkenborg makes something original and beguiling from his sources. Timothy is a deeply reflective tortoise. She watches vipers, swallows and bees; most of all, she watches men. She notices their frenzied and ungainly busy-ness, "the velocity of their existence", so far from her labour-saving lifestyle. She chides their rage for order (in matters of husbandry, sex and society) in spite of the desire-driven "ruck of their lives". And she shakes her head - slowly, of course - over the conceited religion that leads them to preen about "the distinctness of their being" and disparage every other creature on the Earth.

In short, Timothy is a gently sceptical philosophe of the Enlightenment, a hard-shelled, long-lived Voltaire of the cabbage-patch. Cleverly, Klinkenborg gives her thoughts a tortoise-like gait of brief, crisp phrases allied to incremental argument: small steps on a long march. You'd bet on Timothy against a high-flown hare any day. Stranded in "the oat-green glory of this all-too-human place", she treats White the "man of system" as, with his fellow-villagers, "merely a beast like any other". If Timothy had lasted another half a century, she might have felt more at home in Mr Darwin's plot.