The law should provide clear guidance and treat like cases alike. The common law extends principles by reasoning and incomplete analogy, which critics and reluctant practitioners say makes its guidance uncertain and unpredictable. But on the other hand, legislators and regulators often can offer no more than Delphic predictions and broad guidance.

Judges engaged in common law reasoning and instructing juries in particular cases can both extend the law and reassure people that justice will be done in the myriad of individual cases that life’s circumstances present. An exemplar of such reasoning is presented by the Appellate Division in its recently published decision in Diaz v. Reynoso, Dominguez, City of Englewood et al. Vladimir Diaz was gravely injured on Route 4 in Bergen County when his Jeep was rear-ended by a sedan driven by Herbert J. Reynoso. A group of friends had spent a long evening at a private party in Fort Lee followed by a visit to the El Tango Argentino Grill. When Reynoso headed home he turned the wrong way onto a one-say street. Englewood police officer Anthony Gallo and his partner came upon Reynoso who called a friend—Angel Dominguez—to drive Reynoso’s car. Reynoso was ticketed but not tested for sobriety.