There is a distinction between philosophy of law and 'a' philosophy of law. Legal philosophy inquires into the problems of terminology, legal methods, the role of precedent, statutory interpretation, underlying rationale, the use of different types of authority, the efficacy of various controls, and their operation in diverse factual scenarios, and the basic issues concerning the values implemented. 'A' legal philosophy refers to the specific answers to the aforementioned basic inquiries by respectable thinkers on the bench and in academia. Jurisprudence is a body of law that has formal features, and jurisprudential temperament determines whether the case result is found in the jurisprudence; requires a choice between two competing precepts, also in the jurisprudence; or requires recourse to first principles. Based on the aforementioned factors this article examines the meanings of the judge as 'lawmaker' and as 'declarer of public policy.' Other variables in Federal judicial decisionmaking examined are constitutional law interpretation and statutory construction. The necessity for 'reasoned elaboration,' regardless of legal philosophy, is discussed as an important factor in judicial decisionmaking. 293 footnotes.