appears we shall be like him, for we shall see him as he is
Jn 3:2). The whole panorama of the economy of salvation is
directed towards the accomplishment, the consummation
of our life in the communion of the Blessed Trinity through
our adoptive participation in Christ—becoming like him
through grace and the Holy Spirit. Only within this context
can the doctrine of original sin be properly expounded and
understood. Specifically, Aquinas locates the discussion of
original sin within the treatment of the intrinsic and ex-
trinsic principles of human action, where it falls under the
category of external causes of personal sin.
When Aquinas asks whether “sin caused by origin” is
among the external causes of sin, what is themeaning of the
affirmative answer that divine revelation requires of him?
The question is framed in this way: “
Utrum primum pec-
catum hominis derivetur per originem in posteros
or not man’s first sin passes by way of origin to posterity.
Since revelation tells us that sin is in every man born of
Adam by propagation, and not merely by imitation, but
does not tell us just how it is transmitted, Aquinas confines
himself as strictly as possible to its natural origin and avoids
speculation about the mode of transmission.
His restraint here is inmarked contrast to positions ad-
vanced by theologians both before and after him. Especially
among those following Saint Augustine, transmission is as-
sociated with sexual intercourse itself—an act swept along
by disordered libido. A kind of active concupiscence—a
positive disorder or vice—comes to be identified as original
sin transmitted in the act of generation.
Aquinas will have nothing to do with this line of expla-
nation, in large part because he regards it as unnecessary.
“Where authority is wanting,” he famously wrote elsewhere,
8 ST 1a2ae. 81, 1