No Free Lunch: The Significance of Tiny Contributions

There are ten thousand men in the desert, suffering from intensely painful thirst. We are a group of ten thousand people near the desert, and each of us has a pint of water. We can’t go into the desert ourselves, but what we can do is pour our pints into a water cart. The cart will be driven into the desert, and any water in it will be evenly distributed amongst the men. If we pour in our pints, the men’s suffering will be relieved. The problem is, though, that while together these acts would do a lot of good, it does not seem that any individual such act will make a difference. If one pours in one’s pint, this will only enable each man to drink an extra ten thousandth of a pint of water. This is no more than a single drop, and a single drop more or less is too miniscule an amount to make any difference to how they feel. If this is right, it’s unclear why any of us has reason to add our pints. Yes, these men are suffering, but if adding my pint will not make a difference... then what reason do I have to do so?