The Appellate Advocate's Bread and Butter
In his book, Logic for Lawyers, Judge Ruggero Aldisert emphasizes the process of analogy as one of the most importance studies that an appellate lawyer can learn. He writes:
Analogies can be considered the most important aspect of the study and practice of law. It is the method by which putative precedents are subjected to the acid test of searching analysis. It is the method to determine whether factual differences contained in the case at bar and those of the case compared are material or irrelevant. This requires counsel to be intellectually responsible at all time, to consider the consequences of projected steps when they reasonably follow from any position taken or about to be taken. Intellectual responsibility means integrity; it means recognizing the true consequences of any proposition or belief. It is irresponsible to cling to a proposition without acknowledging those consequences that will logically flow from it. If it is necessary to abandon the idea, do it, then move to another theory. If you don't, your opponent will kill you.
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The importance of legal reasoning by analogy cannot be overstated. It is the heart of the study of law; it lies at the heart of the Socratic method in the classroom and in the courtroom. It is important for professors to use the Socratic method, because the method of analogy goes to the fundamentals of the common-law tradition. Cardozo has taught us that "[t]he common law does not work from pre-established truths of universal and inflexible validity to conclusions derived from them deductively. Its method is inductive and it draws its generalizations from particulars.