Such proof Mill attempted to furnish. [Footnote: He does not regard his doctrine as provable in the usual sense; but he adduces what he regards as "equivalent to proof." _Utilitarianism_, chapter i. ] He argues as follows: "The only proof capable of being given that an object is visible, is that people actually see it. The only proof that a sound is audible, is that people hear it; and so of the other sources of our experience. In like manner, I apprehend, the sole evidence it is possible to produce that anything is desirable, is that people do actually desire it. If the end which the utilitarian doctrine proposes to itself were not, in theory and practice, acknowledged to be an end, nothing could ever convince any person that it was so. No reason can be given why the general happiness is desirable, except that each person, so far as he believes it to be attainable, desires his own happiness. This, however, being a fact, we have not only all the proof the case admits of, but all which it is possible to require, that happiness is a good: that each person's happiness is a good to that person, and the general happiness, therefore, a good to the aggregate of all persons. Happiness has made out its title as _one_ of the ends of conduct, and, consequently one of the ends of morality." [Footnote: _Utilitarianism_, chapter iv.] That happiness is the _only ultimate_ end, Mill regards as established by the argument that other things, for example, virtue, though they come to be valued for themselves, do so only through the fact that, originally valued as means to the attainment of happiness, they become, through association, valued even out of this relation, and thus treated as a part of happiness. [Footnote: _Ibid._] The defects in Mill's argument have made themselves apparent, not merely to the opponents of utilitarianism, but even to its advocates. [Footnote: SIDGWICK, _The Methods of Ethics_, Book III, chapter xiii, Sec 5] We cannot say that things are desirable in any moral sense, simply because they are desired. In a loose sense of the word, everything that is or has been desired by anyone is desirable--it evidently can be desired. When we say no more than this, we say nothing. But when we call a course of action desirable we mean more than this; and we are compelled to admit that a multitude of desirable things are not generally desired. This is the burden of the lament of every reformer.