The reason of utilitarianism in support of the use of happiness is the criterion of action. The opinion that the human natural honey happy hate suffering. Every man, whoever he is. When do will aim to find happiness. To avoid suffering. So the utilitarianism therefore concluded that happiness is the only thing of value for human beings.
For this reason, thus proposed that utilitarianism When we have to choose between two actions, how to choose, it is considered that the action will lead to each the result? Will cause much, suffering much happiness when we can compare. Action pose the greatest pleasure, we should choose the action.
By this happiness not only their own pleasure. But have spread to many or most is the overall happiness of every human being received from the effects of actions. The neutral is not the happiness of the precedence over the happiness of others. Whether it is happiness of all were equally important. Then consider the happiness of all the actions together.