Reasoning by analogy may be rule-based or fact-based. Rule-based analogical reasoning involves two steps. The first step is to identify an existing rule that is proposed to be applied to the case to be decided because it is analogous to that case – the given rule. The second step is to determine whether as a matter of social propositions the given rule cannot be distinguished from the case to be decided and therefore should be applied to that case by analogy. Common law courts seldom reason by analogy because a court would never reason by analogy if the case before it is governed by a rule and the common law is thick with rules. Rule-based analogy is a weak form of legal reasoning because often a court must pick from competing analogies so that rule-based analogical reasoning is unpredictable. Fact-based analogical reasoning is based on a factual similarity between the case to be decided and a prior case that is proposed as an analogy. It is weak for the same reason.