abstract. Throughout the common-law world, there is no liability for negligence unless the defendant breached a duty of care owed to the plaintiff. But when is such a duty owed? In the foundational judgment of English negligence law in 1932, Donoghue v. Stevenson, Lord Atkin asserted that “there must be, and is, a general conception of relations giving rise to a duty of care.” Lord Atkin thereby gave expression to the view that the law cannot treat the collection of duties as a chaotic miscellany of disparate norms. Rather, the systematic nature of legal norms requires both that all duties of care be thematically unified through the same underlying principle and that each particular duty be internally coherent. More recently, however, courts seem to have given up on the attempt to formulate or appeal to a general conception of duty and have returned to the multiplicity of particular duties that Lord Atkin deplored. This has caused a “disintegration of duty.”

The general conception of the duty of care – its theoretical basis, its structural constituents, its more recent disintegration back into particular duties, and the need to recapture what a general conception of duty implies – is the subject of the present chapter. It first shows through an analysis of the landmark cases of the Twentieth Century how duty fits with other negligence concepts (failure to exercise reasonable care, factual causation, and proximate cause) to connect the defendant's act to the plaintiff's injury in a normatively coherent way. It then sets out the internal structure of the duty of care, that is, what its constituents must be if it is to reflect a coherent conception of wrongdoing.

In a well-known article, Duncan Kennedy has stated that the central problem for law is its treatment of the fundamental contradiction of our condition. On the one hand we are dependent on others for protection against destruction and for the fullest realization of our sense of ourselves; on the other hand we recognize in others a threat to our own well-being. Kennedy regarded the dilemma “that relations with others are both necessary to and incompatible with our freedom” as the essence of every legal problem, and he ascribed to the liberal conception of law the historical function of dressing up as rational or natural the structures of bondage that emerged as its particular resolutions. Kennedy's contradiction invokes the recurrent tension between the notions of liberty and community that supply traditional vantage points for the analysis of social and political relations. The reconciliation of these notions poses an enduring philosophical problem, and one need not agree with Kennedy's unflattering assessment of the law's function to realize that it is a problem in which law too has been centrally implicated.

My concern in this essay will be the way in which private law, especially tort law, deals with this dilemma. Several considerations justify attention to the theory of private law. First, no-one can read the great classics of Western political and moral philosophy without being impressed by the hold that private law has had on such writing.