Section — Noldin, Summa of Moral Theology
Section 6. Exercise of Medical or Surgical Art.
496. Because of the Exercise of Medical or Surgical Art these are irregular: clerics who exercise the medical or surgical art forbidden to them, if death follows from it.1
a. This irregularity affects only clerics who exercise the medical or surgical art forbidden to them. Those to whom by apostolic indult it is licit to exercise medicine or surgery, as not rarely happens in regions of missions, do not become irregular even if death follows from their care.
b. A cleric contracts irregularity whatever kind of medicine or surgery he exercises; for all are forbidden to clerics in an equal way.2
c. In order that irregularity be induced, it is necessary that the very exercise of his art be the cause, not only the occasion, of death, if death follows from it.
1 Cn. 985, 6.
2 Cn. 139, 2.