Slippery Slopes, Camel's Noses & Floodgates
The Problem of Line Drawing in Legal Reasoning
Mary Massaron Ross*

At the Second Annual Conference of the Council of Appellate Lawyers, Professor Eugene Volokh discussed the mechanisms of slippery slope arguments. Professor Volokh defined a slippery slope broadly to encompass "all situations where decision A, which you might find appealing, ends up materially increasing the probability that others will bring about decision B, which you oppose." Professor Volokh pointed out that the metaphors we use to describe slippery slope arguments often detract from analysis by obscuring the precise nature of the argument. He urged close attention to the mechanisms that may be at work to create a slippery slope because such analytical precision will advance the persuasiveness of the arguments on either side.

Professor Volokh pointed out that slippery slope arguments arise in a variety of contexts including judicial/judicial decisions, judicial/legislative decisions. Slippery slopes may exist even if there is a principled distinction between decision A and decision B. According to Professor Volokh, the metaphors used to suggest that one decision is more likely to be adopted are often employed in a manner that suggests that there is only one mechanism at work. But Professor Volokh believes that many mechanisms exist, and has attempted to refine the concept of the slippery slope by describing these mechanisms. Mechanisms that may operate to make a second disfavored decision more likely as a result of an initial decision include what Professor Volokh describes as small change tolerance slippery slopes, political power slippery slopes, political momentum slippery slopes, attitude-altering slippery slopes, and administration cost slippery slopes.

Professro Volokh's analysis of how these slippery slope mechanisms operate depends on a number of concepts drawn from economic and probability theory, including the operation of multi-peaked preferences, path dependence, and uncertainty curves. His abstract and mathematical approaches are grounded in practical everyday examples and illustrations to help make them understandable. For those of you who missed the seminar presentation, Professor Volokh's ideas will be published in a forthcoming issue of the Harvard Law Review as "The Mechanisms of the Slippery Slope." The next time you see a slippery slope argument, this analysis will help you evaluate its strength and improve your ability to respond to it.

* Mary Massaron Ross is a shareholder at Plunkett & Cooney and heads the firm's appellate practice group. A former law clerk to Associate Justice Patricia J. Boyle of the Michigan Supreme Court, she has over 40 published opinions to her credit.