Precedent: What it is and What it Isn't; When Do We Kiss it and When Do We Kill it?

32 Pages Posted: 28 May 2009 Last revised: 30 Jun 2009

See all articles by Ruggero J. Aldisert

Ruggero J. Aldisert

United States Court of Appeals for the Third Circuit

Date Written: 1990


The doctrine of precedent is everyone's dragon. If facts in the putative precedent are identical with or reasonably similar to those in the compared case, the precedent is recognized as legitimate, and it is applied. In such cases, all of us -- student and professor, lawyer and judge, commentator and philosopher -- consider it merely, as the Italians say, "un dragonetto" (a small dragon). But if the material facts in the compared case do not run on all fours with the putative precedent, the doctrine becomes "un dragone," or, to give equal time, "una dragonessa" (a full grown, ferocious dragon). Wrestling with such a dragon can be the most difficult and controversial job in the judging business.

I realize that literature on how to deal with this dragon abounds. Undeterred, I make bold to mount my charger, draw my lance, and gallop into the lists to volunteer some advice on how to tweak the dragon's tail. Perhaps the dragon will prove too elusive, or I too bold or too meek, but ever persistent I will press on, hoping to tame this dragon. I bring with me experience, not only as a judge, to be sure, but also as one who has explored and meandered in the judicial process thicket, seeking trails to understand what it is all about.

First I will discuss some definitions of precedent and the overarching doctrine of stare decisis. I the will explore what I call the four different models of precedent. From this I will move to a consideration of precedent as a method of classification containing varying degrees of abstraction. This will lead to a study of inductive reasoning, including both generalization and analogy, taking freely from my book Logic For Lawyers: A Guide to Clear Legal Thinking. I wrap it up with some views of precedential vitality, and close with the distinction between precedent and persuasive authority.

PDF scan posted with permission of the Pepperdine Law Review.

Keywords: precedent, judicial process, judiciary, judges, judging, stare decisis, authority, persuasive authority, logic, inductive reasoning, analogical reasoning, inductive reasoning, doctrine, legal logic, logic for lawyers, Aldisert

Suggested Citation

Aldisert, Ruggero J., Precedent: What it is and What it Isn't; When Do We Kiss it and When Do We Kill it? (1990). Pepperdine Law Review, Vol. 17, No. 605, 1990, Available at SSRN:

Ruggero J. Aldisert (Contact Author)

United States Court of Appeals for the Third Circuit ( email )

601 Market Street
Philadelphia, PA
United States

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