“What if I told you that you, too, can save a life, even many lives? Do you have a bottle of water or a can of soda on the table beside you as you read this book? If you are paying for something to drink when safe drinking water comes out of the tap, you have money to spend on things you don’t really need. Around the world, a billion people struggle to live each day on less than you paid for that drink.”

Singer begins the book by prodding his readers with a simple challenge: to think of how much good they could accomplish sacrificing so little. The bottles of water and/or cans of soda signify the minimal sacrifices necessary to do substantial good in the lives of the poorest individuals on Earth. When so little is required to make a difference, Singer implores his audience to question how it could possibly be morally legitimate not to act. His answer is clear: It couldn’t be.

“We can liken our situation to an attempt to reach the summit of an immense mountain. For all the eons of human existence, we have been climbing up through dense clouds. We haven’t known how far we have to go, nor whether it is even possible to get to the top. Now at last we have emerged from the mist and can see a route up the remaining steep slopes and onto the summit ridge. The peak still lies some distance ahead. There are sections of the route that will challenge our abilities to the utmost, but we can see that the ascent is feasible.”

Singer employs a metaphor to show that human beings are finally in a position to end absolute poverty and its adjacent ills. For all of human history up to this point, that possibility was out of reach. Eliminating poverty will not be easy, Singer writes, but it is feasible. The clearing above the clouds signifies the clarity with which humanity can progress if it has the courage and intelligence to do so.

“This suggests that when prompted to think in concrete terms, about real individuals, most of us consider it obligatory to lessen the serious suffering of innocent others, even at some cost (even a high cost) to ourselves.”

Singer contends that most people believe that the welfare of others is more important than their own material comfort. People’s behavior on a concrete, individual level reflects this belief, but on an abstract and anonymous level, they fail to act on it.