  Arguments from precedent and analogy are two central forms of reasoning found in many legal systems, especially ‘Common Law’ systems such as those in England and the United States. Precedent involves an earlier decision being followed in a later case because both cases are the same. Analogy involves an earlier decision being followed in a later case because the later case is similar to the earlier one. The main philosophical problems raised by precedent and analogy are these: (1) when are two cases the ‘same’ for the purposes of precedent? (2) when are two cases ‘similar’ for the purposes of analogy? and (3) in both situations, why should the decision in the earlier case affect the decision in the later case?