International Legal Evangelism: Intelligence, Reconnaissance & Missions

theory.” 152 The application of ius cogens norms in international law is, therefore,
best understood as the direct application in international affairs of natural law
principles.
Mary-Ellen acknowledges that there is a problem of subjectivity: “How do
we avoid … natural law … being the subjective opinion of any one person—
scholar, judge, world leader?” 153 The text of a treaty at least is identifiable. But
natural law is problematic and controversial. “The fact that natural law is derived
from revelation and/or reason presents a problem about reaching consensus as to
what the law is, once the authority of priest or pope was lost.” 154 Mary Ellen
believes that this problem can be mitigated by the work of courts, sifting and
developing a common consensus as to what these ius cogens norms really are. 155
But of course the further we go in this direction, the more we lose touch with the
idea that natural itself operates directly in the international realm.
In fact, conventional wisdom in international law does not identify ius
cogens norms with natural law. According to Marti Koskenniemi,
[a] norm is jus cogens, we think, not because it was so decreed by God, or
because according to this or that theory it is necessary for the survival of the
human species. It is jus cogens if and inasmuch as, to quote Article 53 of the
Vienna Convention on the Law of Treaties, it “is a norm accepted and
recognised by the international community of States as a whole.”’ Jus
cogens, like any other norm, emerges from social life, the observable
interaction between States, the meeting of their wills and interests. 156
Even Jean Porter, O’Connell’s colleague at Notre Dame, in her new book,
Ministers of the Law, which makes a strong case for natural law reasoning,
recognizes the importance of a sort of dialogue back and forth between custom and
direct moral insight. Though she insists, with O’Connell, that “the common
consent of humanity [can] not do away with fundamental rights, or sanitize certain
kinds of atrocious conduct,” 157 she accepts that the basic principles that are
involved here “are necessarily specified to some degree through the generally
152 Ibid., 132.
153 Ibid., 132.
154 Ibid., 137.
155 She says, of “[t]he move to courts to ascertain international law’s higher principles,” that “[s]tates and
organizations have established courts for decision-making and empowered them to decide” (138-9), and she cites
the transparency of their reasoning as a way of avoiding “[o]verly subjective decision-making” (139).
156 Martti Koskenniemi, “International Law in a Post-Realist Era,” (1995) 16 Australian Year Book of International
Law 1, at p. 3.
157 Porter, Ministers of the Law, p. 343.
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