generosity can be made legally obligatory. No court, for example, could justly take upon itself the task of saying that in such and such cases it would compel the giving of alms. If in some instances, then, it enforced the duty of generosity, and in some it refused, it will become necessary to establish some criterion whereby to distinguish those in which it could act from those in which it could not. The courts have never consciously undertaken such a task, and would undoubtedly deny their essential power to attempt it.[1]
Assuming, however, that some such principle were established, the remedy of the plaintiff is by way of damages for a breach of obligation, and not by way of restitution. Neither would it avail the doctrine of unjust enrichment. The measure of recovery is the plaintiff's loss, and it is only accidental, and perhaps not true in all cases, that the plaintiff's loss equals the defendant's enrichment. Even if it were always true, however, the result would be that the doctrine of unjust enrichment would include divergent forms of remedy ascertained by several and independent modes of analysis. It would therefore violate the canons of scientific classification. Moreover, it is an unnecessary link in the chain of reasoning, because, before the injustice is established, the rights of the parties are already determined. The doctrine is therefore mere surplusage.
It is of course impossible to meet in anticipation all the arguments that may be advanced in opposition to the principle of restitution; but there is one query which will at once occur even to those readers who possess only the rudiments of legal learning, and which bears a special relevancy to the question of justice. Where with reference to this principle are to be classified the remedies granted upon mistake? The question is so important that it should receive a commensurate attention.
The learned author assumes without argument that mistake, when the defendant has profited and the plaintiff has lost thereby, is a ground of recovery upon the doctrine of enrichment, and he has contented himself with merely distinguishing a payment under mistake from a voluntary payment with knowledge of the facts,
- ↑ See ante, p. 495. Of course, if the duty of contribution were expressly grounded upon any such theory, we should be forced to admit that the duty of co-operation is sometimes enforced by the court of its own mere motion. Until the court takes that express position, however, it is preferable to regard these decisions as based upon a misapprehension.
