As interpreted by the Catholic Church, NLT has had an enormous influence on the practice of American medicine. In particular, the Catholic Church has interpreted NLT in such a way as to imply the following two highly relevant principles:
The Principle of Double Effect (PDE)
An action X which has a good consequence (GC) and a bad consequence (BC) is morally permissible only if the intention in performing X is to bring about GC and bringing about BC is unintended.
Four requirements must be met for the application of PDE:
i. Action X must be morally good or morally indifferent.
ii. BC must not be the means to GC.
iii. The intention in performing X must be GC alone.
iv. GC must be at least as important as BC.
An example of the application of PDE may help make sense of it.
Suppose a woman is three months pregnant and has a cancerous uterus. Then,
X = Removal of the uterus.
GC = The woman's life is saved.
BC = The fetus' life is lost.
PDE implies that X, removal of the uterus, is morally permissible even though it necessarily results in the loss of the fetus because each of the four requirements is satisfied, and the intention in removing the cancerous uterus is to save the woman's life--not to destroy the fetus.
The Principle of Totality (PT)
Any action of destroying or altering the function of an organ is permissible only if the action is required for the general well-being and preservation of the whole body.
A few obvious examples are suggested.
Vasectomies and tubal ligations are impermissible in most circumstances by PT.
Virtually all instances of plastic surgery are impermissible by PT.
I leave it as an exercise for the curious student to see how, under the Catholic Church's interpretation, NLT implies PDE and PT.