Modern biblical interpretation and evolutionary sci-
ence clearly pose challenges to the Catholic doctrine of
original sin. But the approach of Aquinas in addressing
difficulties of this kind, in contrast to much secular think-
ing, teaches us to take our methodological orientation from
the criterion of intelligibility rather than the criterion of
reasonableness. It is a theology that arises from faith seek-
ing understanding. It does not put God to the test, as if he
could be called to the bar of human reason. Rather, it is a
theological approach that acknowledges the limits of human
rationality and the unlimited character of the intelligibility
of divine truth and the divine plan in which it is manifested.
It is in this light that Aquinas offers his explanation
of our membership in the human race as a way of un-
derstanding, in line with Catholic doctrine, how original
sin could be said to have been transmitted—how sin and
death entered the world through one man—and how, “as
sin reigned unto death, so also grace might reign by justice
unto life everlasting, through Jesus Christ our Lord.”While
the criterion of reasonableness allows only what makes
sense to us, the criterion of intelligibility draws the human
mind into the fullness of divine truth.
Divine explanation for the existence of moral evil:
original sin as revealed
G.K. Chesterton famously remarked: “Certain new
theologians dispute original sin, which is the only part of
Christian theology which can really be proved.”
19
Although
embedded in a complex argument, this often-quoted remark
is one that people find appealing. The evidence for original
sin is all around us, they seem to say, in the moral evil we
can “see in the street.”
19
Orthodoxy
, 3