KEENER ON QUASI-CONTRACTS. 501 be the identical thing that the defendant gains, does not appear in the doctrine of enrichment, nor does it appear that by injustice is intended merely a tort or a breach of a consensual obligation. In every case, however, where, in addition to the conditions contained in the doctrine of enrichment, it is also true that the injustice lies in a breach of a consensual obligation or in a tort, and that the property or service whereby the defendant is enriched is also the property or service which the plaintiff has lost, the principle of restitution is applicable. The cases cited and discussed by the learned author in his chapters entitled " Waiver of Tort " ^ and "Obligation of a Defendant in Default under a Contract," ^ almost uniformly fall within the lines of both doctrines, and so far as that is true I am glad to avow myself in accord with the learned author. A particular discussion of such cases, therefore, is not necessary. It is in the discussion of cases in which the two principles differ that the greatest intellectual profit and the clearest mutual under- standing lie, and therefore, ungracious though it seem, it is on the differences rather than on the agreements that stress will be laid. As has been seen, the word unjust may have a wider scope than merely the breach of the obligations enumerated in the principle of restitution. It behooves the careful critic, therefore, to analyze the distinction between the two. Now the learned author has attempted no definition of injustice. This cannot be regarded as otherwise than a very serious and fundamental omission by a writer who is endeavoring to establish a new principle based upon justice. It necessarily invalidates as an argument every discussion upon which he enters, simply because it deprives him of a major premise. There are for him no criteria of the general class of unjust acts whereby to determine a given case. We may admit, for argu- ment's sake, that a tort is an unjust act ; but if some other reader less tolerant should refuse to make the admission, how could the author substantiate his position that one who enriches himself by a tort is unjustly enriched.^ This is, of course, an extreme case, and the learned author may say, with some justice, that he had no intention of writing a book on jurisprudence in general, and that he took certain results of jurisprudence as fully determined. This plea will not avail him, however, in cases where there are no such fully determined results. Thus he concludes that the plaintiff should be allowed to recover from the defendant in a case where 1 Pages 159-213. ^ Pages 267-314.
