will weave them into the unity of a stable system, and make of the world what one may call a genuine universe from the ethical point of view. So far as the world resists reduction to the form of unity, so far as ethical propositions seem unstable, so far does the philosopher fail of his ideal. The subject-matter of his study is the ideals he finds existing in the world; the purpose which guides him is this ideal of his own, of getting them into a certain form. This ideal is thus a faction in ethical philosophy whose legitimate presence must never be overlooked; it is a positive contribution which the philosopher himself necessarily makes to the problem. But it is his only position contribution. At the outset of his inquiry he ought to have no other ideals. Were he interested peculiarly in the triumph of any one kind of good, he would pro tanto cease to be a judicial investigator, and become an advocate for some limited element of the case.
There are three questions in ethics which must be kept apart. Let them be called respectively the psychological question, the metaphysical question, and the casuistic question. The psychological question asks after the historical origin of our moral ideas and judgements; the metaphysical question asks what the very meaning of the words 'good,' 'ill,' and 'obligation' are; the casuistic question asks what is the measure of the various goods and ills which men recognize, so that the philosopher may settle the true order of human obligations.