from... http://www.economist.com/node/16160773
WHEN George Price died in January 1975, his funeral in London was attended by five homeless men: dishevelled, smelly and cold. Alongside them were Bill Hamilton and John Maynard Smith, both distinguished British evolutionary biologists. All seven men had come to mourn an American scientist who helped to unpick the riddle of why people should ever be kind to one another, who had chosen to give away his clothes, his possessions and his home, and who, when his generosity was exhausted, slashed his own throat with a pair of scissors, aged 52.