with trying to reward voluntary actions in proportion to the worth of the services intentionally rendered by them. If, then, we take as the principle of ideal justice, so far as this can be practically aimed at in human society, the requital of voluntary services in proportion to their worth, it remains to consider on what principle or principles the comparative worth of different services is to be rationally estimated. There is no doubt that we commonly assume such an estimate to be possible; for we continually speak of the ‘fair’ or ‘proper’ price of any kind of services as something generally known, and condemn the demand for more than this as extortionate. It may be said that the notion of Fairness or Equity which we ordinarily apply in such judgments is to be distinguished from that of Justice; Equity being in fact often contrasted with strict Justice, and conceived as capable of coming into collision with it. And this is partly true: but I think the wider and no less usual sense of the term Justice, in which it includes Equity or Fairness, is the only one that can be conveniently adopted in an ethical treatise: for in any case where Equity comes into conflict with strict justice, its dictates are held to be in a higher sense just, and what ought to be ultimately carried into effect in the case considered--though not, perhaps, by the administrators of law. I treat Equity, therefore, as a species of Justice; though noting that the former term is more ordinarily used in cases where the definiteness attainable is recognised as somewhat less than in ordinary cases of rightful claims arising out of law or contract. On what principle, then, can we determine the “fair” or “equitable” price of services? When we examine the common judgments of practical persons in which this judgment occurs, we find, I think, that the ‘fair’ in such cases is ascertained by a reference to analogy and custom, and that any service is considered to be ‘fairly worth’ what is usually given for services of the kind. Hence this element of the notion of Justice may seem, after all, to resolve itself into that discussed in § 2: and in some states of society it certainly appears that the payment to be given for services is as completely fixed by usage as any other customary duty, so that it would be a clear disappointment of normal expectation to deviate from this usage. But probably no one in a modern civilised community would maintain in its full breadth this identification of the Just with the Usual price of services: and so far as the judgments of practical persons may seem to imply this, I think it must be admitted that they are superficial or merely inadvertent, and ignore the established mode of determining the market prices of commodities by free competition of producers and traders. For where such competition operates the market value rises and falls, and is different at different places and times; so that no