Catholic Catechism:
2515
Etymologically,
"concupiscence" can refer to any intense
form of human desire. Christian theology has given it a
particular
meaning: the movement of the sensitive appetite contrary
to the
operation of the human reason. The apostle St. Paul
identifies it
with the rebellion of the "flesh" against the
"spirit." Concupiscence
stems from the disobedience of the first sin. It
unsettles man's
moral faculties and, without being in
itself an offense,
inclines
man to commit sins.
