INFERENCE PATH

Ask almost any litigator to define an ”enthymeme” and you will get back a blank stare. But while they likely don’t know that term, successful litigators are experts at filling in the blanks of arguments with implicit premises (i.e., enthymemes). One of our fundamental jobs is to x-ray our opposing counsel’s argument to reveal implicit premises in search of the argument’s weaknesses.

To be successful at this uncovering process, a theory of enthymemes would be helpful. For example, Dr. Douglas Walton presents an intriguing academic theory on enthymemes. http://io.uwinnipeg.ca/~walton/papers%20in%20pdf/07ThreeBases.pdf. For practical purposes in litigation, however, it is less efficient.

The main cause of this inefficiency in litigation is its lack of a single precise design template for any argument that can act as scaffolding for its complete construction. Dr. Walton’s theory, based on CBVK, depends on the litigator knowing many templates to try to find a fit rather than just one. This burdensome complexity is the “36 tricks of the fox compared to the one trick of the hedgehog” issue. Using (defeasible) essential predication transitivity as the sole argument design avoids this burden. (See this post for the possible defeasible nature of essential predication transitivity.) And in the rapid dialogic context of oral argument in court, the litigator needs the most efficient approach.

Since in litigation the conclusion is typically explicit, the first step using the essential predication transitivity (defeasible) design is to separate the subject and predicate of the conclusion into two premises such that the subject of the conclusion is the subject of one premise and the predicate of the conclusion is the predicate of another premise. This step binds the argument at both ends which is not possible using a tree-like approach. Once the ends of the argument are defined, the intervening linking inferential premises are found relying upon the explicit premises and the transitivity pattern. If any inferential leap is found too big, the granularity can be increased. Finally, any necessary underlying assumption premises are determined by simply asking what premises must be acceptable to support a specific inferential premise.

The following argument maps illustrate this essential predication transitivity (defeasible) approach (along with Dr. Walton’s maps) using the arguments drawn from his excellent paper.