Causation in the tort of negligence is a "legal minefield" that any philosopher, scientist or lawyer is to tread "with trepidation" (at p 1). To deal with causation, courts have developed an array of tests with seemingly no coherence. Should courts apply the 'doubling the risk' test or reverse the burden of proof? Or should the Fairchild exception apply? In Causation in Negligence, Sarah Green ambitiously proposes an analytical framework that "eschews detailed philosophical and theoretical handwringing in favour of pragmatic reasoning" (at p 1). Green claims that her framework, which she calls the Necessary Breach Analysis ("NBA"), provides an accessible way to approaching causal problems.

As explained in the preface, this book is the product of a research project started a decade or so ago. It is based on a doctoral thesis. The author has wisely avoided a rush to publication. Her efforts have resulted in an ambitious and intriguing theory of justice and law. It is founded on the notion of friendship as explicated principally through the work of Aristotle. There is little written on friendship in law although there is an emerging body of literature on the related topics of law and love, and law and virtue.

Conduct amounting to a breach of duty often causes loss to the person to whom the duty is owed. But sometimes the duty-holder in breach, being insolvent, is a man of straw not worth suit. Other times, the prospect of suit is unattractive given the possibility of jeopardising existing relations with the duty-holder. To seek an adequate remedy, one is then tempted to expand one's search to the surrounding circumstances leading up to the breach. So we peer up the chain of events. We search for persons—accessories—whose conduct contributed to the objectionable outcome. But the further up you go, the more diluted the contribution. And that presents a problem.