The common law is easy to experience; not so easy to describe. To this reviewer, it looks like a gigantic and endless ballet of thousands performing at a time with individuals constantly entering or leaving the stage. Some stay for a few moments and simply repeat the steps of others. A number take the opportunity to improvise small new patterns. A few soar for long periods. At different times, each participant is a dancer, a choreographer, or a member of the audience. It is a real challenge to describe in simple terms the music to which all respond in their work. Professor Richard Cappalli of Temple University School of Law has succeeded. He has written a remarkable hornbook about this difficult subject.

As a guide for students, his treatise appropriately seeks to identify the melodies, leaving to others to explore the orchestration. The result may seem a little like hearing ballet music played on the piano, with interruptions by a music appreciation teacher to report what various musicologists have said about each of the musical themes. Experienced lawyers may perhaps find themselves distracted by their memories of what the music sounds like when performed by all of the instruments.

Professor Cappalli opens his work with a quotation from Tennyson’s poem Aylmer’s Field about

His starting point is the observation that what a common law court does is authoritative, not what it says. Only when “extracted and applied” by a later court is the reach and meaning of a precedent known. This produces legal principles which are fact bound and therefore inherently narrower than a legislative code. A court construing a statute traditionally attempts to discern the boundaries of its scope by treating the text as an expression of the legislature’s intentions. But the same court, when dealing with common law precedent, gives little if any consideration to what the earlier court would have done with a new fact pattern.

To be sure, the issuing court provides initial form to the precedent by its description of the facts. The extent to which it goes on to characterize those facts in abstract terms represents an effort to give the case broader future influence—potentially as the source of a rule of general application. But a court breaking new ground, and concerned about where its decision will lead, might well limit itself to a description of just the facts and decline to characterize them at all. So, too, a judge seeking