Peter Singer is a public intellectual par excellence; he takes complex philosophical notions and relates them directly to the general reader without a hint of loftiness or superiority. The Life You Can Save is classic Singer: a straightforward but perspicacious exploration of one of the great ethical questions of our age. Do ordinary people in the West have the power to end world poverty and prevent millions of unnecessary deaths? Singer's answer is a resolute yes, without, thankfully, any of the pseudo-poetic and maudlin self-promotion that permeates similar proselytising by Bono, Bob Geldof and, lately, Bill Clinton.

Working essentially in a didactic mode, Singer concedes that his overriding goal is "to convince you to choose to give more of your income to help the poor". While fulminating against the fashionable cynicism about do-gooders and lost causes, he asserts that with our support, aid agencies like Oxfam have a prodigious scope to prevent deaths due to extreme poverty in most of the world's vulnerable countries. We've heard variations on this view before, but rarely have the arguments been stated with such forensic intensity and with such persuasive accompanying data. Singer strikes just the right tone: he gently mocks Western status symbols and petty ambitions, and he charts with precision how you and I can, and should, snap out of our self-importance and directly help some of the world's poorest people.

A great strength of Singer's thesis is his elimination of hopelessness from the subject. He illustrates the extent of the progress already made, drawing our attention to the fact that in 1960, 20 million children died before their fifth birthday, compared with 10 million in 2007. While still a scandalous statistic, this dramatic reduction is doubly remarkable given population growth over the intervening years, and demonstrates that ending poverty isn't just some slavering and inchoate hippie pipedream.

Some years ago this book might have been called thought-provoking. It would be a great pity if this description were applied to it today. The Life You Can Save is an ineluctable call to action - the prose equivalent of blazing trumpets. By the time you're halfway through it, you may well find yourself making practical arrangements to give away a percentage of your annual income. Just as Singer hopes you will.