Published online by Cambridge University Press: 20 July 2015
In a number of places, Mark Murphy has defended what he calls a ‘weak version’ of the natural law thesis. His claim is that, “law not backed by decisive reasons for action is still law, but defective precisely as law”. In this paper, I attempt to provide an answer on behalf of Murphy to the question: when law is defective, what is it about law that continues to make it ‘law’ despite its being defective? Three separate, but related, strategies are examined; all three – for separate, but related, reasons – are shown to fail. The conclusion drawn is that if Murphy is unable to provide a sufficient answer to the central question of the paper, the viability of his weak natural law theory is thrown into serious question.
1. Murphy, Mark C, Natural Law in Jurisprudence and Politics (Cambridge: Cambridge University Press, 2006) at 1.CrossRefGoogle Scholar
2. Ibid at 9.
3. Ibid at 10.
4. Murphy refers to ‘The Fugitive Slave Act of 1850’ (“requir[ing] citizens not to hinder, and even aid, federal marshals who sought to return runaway slaves to bondage”. Ibid at 8) as an example where, in opposition to the central claim of natural law, a particular law was not backed by decisive reasons for action.
5. See both Green, Leslie, “Legal Positivism”(2009) in Zalta, Edward N, ed, online: Stanford Encyclopedia of Philosophy http://plato.stanford.edu/archives/fall2009/entries/legal-pos-itivism/; and Finnis, John, “Natural Law Theories” (2008)Google Scholar in Edward N Zalta, ed, online: Stanford Encyclopedia of Philosophy http://plato.stanford.edu/archives/fall2008/entries/natural-law-theories/.
6. Murphy, supra note 1 at 14.
7. I write ‘plausible’ since it is certainly not the case that all legal positivists are conventionalists or that for one to be a legal positivist, one must bear a conventionalist attitude toward law. In fact, it has even been argued that positivism should simply cut ties with conventionalism once and for all (see Green, Leslie, “Positivism and Conventionalism” (1999) 12 Can JL & Jur 35)Google Scholar. There are, however, good arguments that support the idea of a strong link existing between positivism and conventionalism (see Postema, Gerald, “Coordination and Convention at the Foundations of Law” (1982) 3 J Legal Stud 165 CrossRefGoogle Scholar and Marmor, Andrei, “Legal Conventionalism” (1998) 4 Legal Theory 509).CrossRefGoogle Scholar
8. Murphy, supra note 1 at 11-12.
9. Ibid at 12.
10. Ibid at 10-11.
11. Moore, Michael, “Law as a Functional Kind” in George, Robert P, ed, Natural Law Theory (Oxford: Oxford University Press, 1992) 188 Google Scholar at 204-05.
12. See Murphy, supra note 1 at 8-24.
13. Ibid at 30.
14. Ibid.
15. Ibid at 33.
16. The problem with this approach is addressed more fully in the next section of the paper, which deals specifically with law’s structure.
17. See Brigandt, Ingo, “Natural Kinds and Concepts: A Pragmatist and Methodologically Naturalistic Account” in Knowles, J & Rydenfelt, H, eds, Pragmatism, Science and Naturalism (Frankfurt am Main, 2011) 171 Google Scholar at 173-75.
18. It is not inconceivable that the structuralist could allow for this—but depending on the level of specificity of his definition, he need not.
19. See Moore, supra note 11 at 223.
20. See Murphy, supra note 1 at 32.
21. Ibid at 31.
22. Ibid at 34-35.
23. Ibid at 34.
24. Ibid at 34-35.
25. Ibid at 23.
26. Ibid.
