What happened a few thousand years ago no longer seems quite so far away in time. It is what islands induce in one, a sense of simultaneity, as well as the old penchant a fool might have for occupying several dimensions at once. And the people who inhabited those ancient places seem more and more like ourselves whereas, at times, our contemporaries become increasingly, troublingly, remote. The islands of the Outer Hebrides have long fostered a culture outside time. Once eroded by the Highland Clearances and persecution of Gaelic, the cornerstones of island culture - stories at the fireside, the singing of psalms, and an intimacy with the past - are now under threat by the trappings of modernity and dominance of the English language. Still, there lingers in most people a desire to tell, and be told, stories: a desire as ancient as oatcakes. Marius Kociejowski's story has heroes - the poets of Upper Bayble, perhaps, or Father Colin MacInnes, champion of the Gaelic language - and villains, like the brutal Donald Munro, who delighted in evicting tenant farmers from his master's land. A history, a travelogue, and much else besides, The Quantum of Happiness distils the elements of joy that exist in this north-westerly corner of Europe and wonders if happiness is truly measurable: or if it moves at such speed through our lives that we don't even notice its passing.