Perhaps we may partly attribute to the difficulties above discussed, that the notion of Desert has sometimes dropped out of the ideal of Utopian reconstructors of society, and `Equality of Happiness' has seemed to be the only end. Justice, it has been thought, prescribes simply that each should have an equal share of happiness, as far as happiness depends on the action of others. But there seems to be much difficulty in working this out: for (apart from the considerations of Fitness above mentioned) equal happiness is not to be attained by equal distribution of objects of desire. For some require more and some less to be equally happy. Hence, it seems, we must take differences of needs into consideration. But if merely mental needs are included (as seems reasonable) we should have to give less to cheerful, contented, self-sacrificing people than to those who are naturally moody and exigeant, as the former can be made happy with less. And this is too paradoxical to recommend itself to Common Sense.