202 HARVARD LAW REVIEW. be chary about imposing irrecusable duties, especially when uni- versal. The general character, then, of these nexus will be that of relations fundamentally necessary to civilized social intercourse, — the minimum number of universal nexus without which (having reference to the points of view of both obligee and obligor) the ■ community cannot get along. This in fact fairly expresses the general character of Tort-rights. Furthermore, and as a result of the same spirit, these Universal Irrecusable Nexus are all negative, not affirmative ; i. e. the line is drawn at requiring others not to be the means of harm to me ; our law has not yet gone so far, in Uni- versal duties, as to impose any affirmative duty, as between one man and another, to take action to confer a good. But, going further than these general features, we easily see, on examination, certain generic component elements in every relation of the sort we are considering. First, there are the specified sorts of harm which the obligor has a claim to be free from ; this is the basis of the obligee's interest, the thing for the sake of which the nexus is instituted. Second, there must be something to connect the obligor with this harm, — that is, we must specify what is the sort of causality-connection, or the like, between the obligor and the harm in question for which he will be held responsible. This is necessary, because the very nature of the nexus presupposes that the obligor is to have some connection with the harm, and it is part of our business to specify when that connection shall be deemed to exist. Third, since human experience has always found it neces- sary to sanction in law the principle of give-and-take, and to compel us sometimes to put up with harm whose source is perfectly clear, there are numerous classes of circumstances to be specified in which the nexus fails, and is without application, — that is, although harm is done, and although there is no question as to a particular person's responsibility for it. These circumstances form limitations to the nexus as a whole. There are, therefore, three distinct classes of limitations dealt with in the law relating to Torts, which may be conveniently termed the Primary, Secondary, and Tertiary limitations. The first class deals with the sort of harm to be recognized as the basis of the right; this may be called the Damage element. The second class deals with the circumstances fixing the connection of the obligor with this forbidden harm ; this we may call the Responsibility ele- ment. The third class deals with the circumstances in which, as- suming both the Damage and the Responsibility elements to be
