One of my former law professors, Harry Kalven, liked to say that "law is the process of choosing among competing analogies." At its core, legal reasoning is about trying to find insight, or logic, or common sense by comparing different situations and then striving to identify the most important similarities and differences. Analogies open some doors and close others. They shape and direct the analysis.
For example, if it is settled that obscenity is not protected by the First Amendment, then what other types of speech are also not protected by the First Amendment? Are depictions of violence protected by the First Amendment? Are depictions of cruelty to animals protected by the First Amendment? Is opera protected by the First Amendment?
To answer these questions, legal reasoning demands that we begin by asking why obscenity is not protected by the First Amendment and then trying to figure out whether these other forms of speech are similar or different from obscenity in these respects. To do this well requires not only knowledge, but insight, creativity, subtlety, and rigor. Because this is the essence of legal reasoning, a critical question is always whether we are starting the inquiry with the best and most helpful analogy.
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