In the twentieth century, tort law drifted incrementally and erratically towards greater generalization and integration. Narrow categories of liability controlled by rules of a low degree of abstraction and discretion, in some instances, gave way to broad and unifying principles. The best example, of course, is Donoghue, where Lord Atkin emancipated the duty of care from specific relationships and brokered a general conception of relationships giving rise to a duty of care known as the neighbour principle. It set the model for negligence principles of a high degree of abstraction which carry a great deal of discretion and facili-
tate flexible and sensitive decision making. This process is also evident in the coalescence of the torts dealing with improper market practices around the concept of intentional interference with economic interests by unlawful means, and in the generality of the nascent tort of privacy. There is also an echo of this process in the insinuation of negligence concepts into other areas of tort law.
The trend to generalization and integration has not, however, been universal. The nominate torts dealing with the intentional interference with the person have proved to be resistant to this process. This is due partly to their antiquity and partly to the lack of cases reaching the appellate level. The tort of conversion has played some role in the integration of the torts dealing with the interference with chattels, but no overriding principle such as one imposing liability for the wrongful interference with chattels has emerged.8The torts of strict liability have maintained their narrow discrete categories. To some degree, this is the result of the judicial policy of containing strict liability within narrow boundaries. A general principle of strict liability for ultra-hazardous activities would invite a considerable expansion in the scope of strict liability. There has also been no integration in the torts...