3. Natural Law
Natural law is multiply ambiguous. It can be descriptive, in that it is sometimes supposed to describe a certain set of facts which obtain because of some natural features. At the same time, it can also be prescriptive, in that it is sometimes supposed to prescribe certain forms of behaviour as acceptable and proscribe others as unacceptable. On another level, its scope or range of application is unfixed. Some natural law theories pertain to political entities (typically states and relations among states); others, to civil laws; yet others, to moral agents. On still another level, the ambiguities can be seen as stemming from the very notions of "natural" and "law." "Natural" can refer to human nature, or to the nature of the universe in general, or both. One's sense of the validity and force of a natural law theory will vary enormously depending on which reference is employed. "Law" was similarly contested. One extreme interpreted it literally, so that a natural law is a rule implemented by some agent (typically God) which compels obedience on pain of some penalty. The other extreme took "law" completely metaphorically, picking out some standard or norm perceivable in natural phenomena which governs behaviour through entirely impersonal means.
Such variation should not be surprising, for the natural law tradition was long and robust. Though there were ties to the ancient world, it began in earnest with Aquinas, since he was the first to formulate a group of ideas systematic enough to be called a theory. The tradition continued through the middle ages and into the early modern era before (allegedly) meeting its demise in Kant. Given that natural law was the dominant paradigm in ethics, politics and law for hundreds of years — much longer than the period from Kant to us — it is entirely predictable that theorists would have pushed that paradigm in so many directions. It may be that there is some essence shared by all natural law theories; for example, one recent commentator has suggested that the "stable core in [the natural law tradition] is the idea that morals is primarily a matter of norms or prescriptions and only derivatively about virtues and values" (Haakonssen (1992), 884). But those who study natural law in the period of its flourishing will be impressed by the almost unlimited possibilities of interpretation.
Though this is not an article on the natural law, these points are necessary preliminaries for considering Grotius' natural law views. If Grotius is at all known to philosophers today, it is for being "the father of natural law" (as put by, e.g., Vreeland (1917)). While this is not untrue, neither is it completely correct. To understand Grotius' views, four issues need to be examined: first, the source of the laws; second, their nature or content; third, their force or obligatory status; finally, their scope. In the process, light will be shed on how he is original and how he isn't.
Why are there natural laws? Do they…