Philanthropy, especially in the form of giving to charities, is a guiding principle of many Americans. Each year millions of dollars and countless hours are devoted to helping others, from donating clothing to the Salvation Army to making out charitable trusts and volunteering in mentoring programs. While some see this as a golden age of giving, prospective donors may wonder how best to manage their contributions. Whatever strategy one uses, there are, of course, no guarantees of success, as Times' columnist David Brooks points out in an opinion article. The best intentions have their limits. And yet the story of a remarkable chain of kidney donations shows the power of the individual to make a difference and to change lives. This esingle is comprised of articles from The New York Times.