i'm not sure which principle you are referring to. if you mean the principle of double effect, it does not apply, since the actions dealt with under this principle are either morally good or morally neutral actions only, and -- as the catechism affirms -- direct abortion is neither morally good nor neutral but "morally evil". having in his encyclical "evangelium vitae" declared as doctrine that "direct abortion, that is, abortion willed as an end or as a means, always constitutes a grave moral disorder, since it is the deliberate killing of an innocent human being", pope john paul ii continues: the circumstance of "grave peril" to the mother's "health and even life" is discussed in pius xi's encyclical letter "casti connubii" but he states that this could never be "a sufficient reason for excusing in any way the direct murder of the innocent" (paragraph 64). both documents acknowledge the tragedy of such a situation and the pain suffered by those intimately involved and those looking on, but pius xi warns against allowing ones feelings -- no matter how strong they are or how noble the motives may seem -- to cloud the distinction between right and wrong. a very pertinent thought for all of us as nurses.