I was reading The Idea of Justice by Nobel Laureate Amartya Sen, now in paperback, and he starts out with the following example.
Take three kids and a flute. Anne says the flute should be given to her because she is the only one who knows how to play it. Bob says the flute should be handed to him as he is so poor he has no toys to play with. Carla says the flute is hers because she made it.
Sen argues that who gets the flute depends on your philosophy of justice. Bob, the poorest, will have the support of the economic egalitarian. The libertarian would opt for Carla. The utilitarian will argue for Anne because she will get the maximum pleasure, as she can actually play the instrument. Sen states there are no institutional arrangements that can help us resolve this dispute in a universally accepted just manner.
I liked the thought experiment better when it was called 'The Little Red Hen'
“I found the wheat, I planted it, I weeded it, and when it was time to harvest it, I did that too. I took it to the mill to be ground into flour and at last, I baked it into bread.
“Now,” said the little red hen, “I’m going to eat it with my family.” And she did.
Nothing more universal and just than telling the cow, pig and cat to go f*** themselves and eating that bread with your family.