Some time ago, two sharp German comparatists paid a decidedly barbed compliment to English law. For all the elegant construction and sophisticated operation of the common law machine, it was (they said) something that nobody in his right mind could ever come up with when charged with designing a legal system from scratch. Looking at the English chattel torts, it is difficult not to conclude that they had a point. Four separate heads of liability (or more, depending on how you count them), involving numerous levels of degrees of fault and intention, introducing sometimes razor-thin distinctions, and filling 80 pretty dense pages of Clerk & Lindsell on Torts; and yet we still puzzle over precisely what interests in or over movables are protected by this congeries of overlapping liabilities, what amounts to tortious infringement of them, and what measure of compensation is awarded when they are.

All this makes particularly welcome Simon Douglas’s refreshingly slim volume on the whole subject. This deals, as might be expected, with all the perennial questions lawyers ask about the chattel torts: for example, whether a contractual, as against a proprietary, interest will allow a claimant to sue; whether intangibles ought to be subject to the same rules as tangibles; or whether equitable owners ought to be able to claim; and so on. All these he answers succinctly (and, in your reviewer’ s view, almost invariably correctly). But there is more to it than that. The thesis underlying the whole book is that, surprisingly enough, there is actually rhyme, and sometimes even reason, behind the property torts, including negligent damage to chattels. If you look carefully enough at them, you can see and extract a fairly coherent scheme of liability. Put briefly, Dr Douglas’s leitmotiv is that all the torts to chattels can be reduced to just two: one of deliberate interference, carrying strict liability; and one of negligent interference, requiring proof of fault.

The argument runs thus. Orthodoxy has it that trespass, conversion and negligence are different in scope; trespass, we are told, is about acts impinging on possession of chattels, conversion about interference with an immediate right to possess them, and negligence about physical lesion to them. Not so, says the author. Actually, all three wrongs deal with essentially the same sin: namely, substantial interference with an owner’s right to the benefit of his goods. Drawing on the chaotic and contradictory nineteenth-century case law, Dr Douglas concludes that trespass does not need any physical interference; and that, on the contrary, there is ample authority that separating owners from goods is just as trespassory as separating goods from owners. As for negligence, despite appearances (and indeed many tort books), there is actually no need for positive harm to goods. True, most cases do concern physical damage: nevertheless, authority is there suggesting that deprivation—as in the case of jewellery stolen but presumably unscathed in the hands of an untraceable thief or fence—will do just as well. And the argument then rolls on. Just as there is a common scope of liability, nor is there any genuine difference in the rules on title to sue. To the immediate objection that trespass is different because a non-possessor cannot bring suit, the riposte is blunt: he can. The orthodox authority against is old, weak and incoherent: per contra, the right of a bailor at will to sue, coupled with the action for reversionary injury available to other reversionary owners, far from being exceptional cases, actually represent the presumptive position. And from this comes the