as secure in particular conclusions as in general principles. However, practical reasoning is
concerned with contingent things belonging to human actions, and so although there is a certain
necessity in its general principles, the more we descend to particulars the more frequently do we
find exceptions. Hence, in practical reason the more we descend to matters of detail, the more
the general principle will be found to admit of exceptions.
A crucial difference between Aristotle and Aquinas is that the element of contingency in
action does not mean that human law, insofar as it is actually law, contains elements of
contingency. Human law is substantially, not contingently, related to natural law, in the sense
that it is contained in the idea of that thing, in an analogous way that soul is contained in the
Whereas nature in Aristotle implied a portion of contingency (as the usually
and for the most part ), nature itself implied no normative meaning at all. Aquinas, on the other
hand, moors his conception of natural law to a transcendental source by defining it as the
practical translation and partial apprehension of divine law. But to the degree that we descend to
particular things through practical reason, we will encounter moments of irreducible
contingency. Insofar as law is means and measure, it isn t contingent. But if a contingency arises
that isn t covered by positive law, the law can be suspended or modified without modifying its
status as law; i.e. it s participation in the idea of a higher order of law.
This is why Aquinas dispenses with the question of whether the letter of the law may be
violated in cases of sudden peril calling for an immediate response. In such cases, Aquinas
answer, like most other medieval legal theorists, was an unequivocal yes.
these instances were relatively unproblematic for him is that they were by definition accidens
inessential to the phenomenon of being subject to the rule of human law. Action outside the law
in certain exceptions did not damage the integrity of the law, nor did it raise any compelling legal
questions because the incident to which the law didn t apply was regarded as by definition only
contingently related to the end to which human law is directed: the common good. Thus,
Aquinas can write, without contradiction, He who in a case of necessity goes beyond the letter
of the law does not judge the law itself, but only the particular case in which he sees that the
latter of the law should not be observed. This passage, absurd to the modern legal mind, is
comprehensible according to the hierarchical ontology outlined above: contingent things relate
13
Ibid.
14
Summa theologiae IaIIae 95 (135).
15
Summa theologiae IaIIae 97, in Aquinas: Political Writings, 148-9, and 154.
7
Convention