What people want

I think all people want happiness. Happiness is the end for which all other endeavors are merely the means. I can't think of a single action worth doing if eventually someone would derive no pleasure from it. Even acts of seeming self-sacrifice bring with them a comfort and pleasure. No rational person would ever choose happiness over unhappiness and because these categories are so broad I think it's fairly safe to say that if all human activity had to be categorized to one end it would be the pursuit of happiness.

The problem becomes seeking this goal. I think the question is deficient because it asks "what is the one principle for which all people strive" and also "what can be done to achieve this principle for the most amount of people." It seems that happiness frequently comes at the cost of another's happiness . The example of a child that made a coat in a sweatshop that is given to a homeless person in winter exemplifies these costs. Is the homeless person at fault for accepting a coat because cruelty was involved in its manufacture? Is the Salvation Army worker at fault for doling the coat out during months when people needed it? Is the CEO of the clothing company at fault if he has broken no laws and uses the added revenue from lowered labor costs to keep his garments competitive and available to poorer people? The attainment of happiness is not guaranteed- only the pursuit is. History seems to be one long project (whether in the fields of economics, culture, politics, or philosophy) in trying to answer the question of how to reconcile this universal want in the most efficient- but never perfect- manner.

PS: I understand the example is far from perfect but it was the first I came up with so please try to focus criticisms on the points of the post. Sorry.