Quentin de la Bedoyere (QB), writing in the Catholic Herald (successive issues, May 2006) raises the question of Captain Oates leaving his companions, on their antarctic expedition, in order to maximise their chances of survival (since he would not be using up stores etc.). Oates simply left the camp and walked into the wilderness to certain death. Was this wrong?
QB addresses one response: it was permissible because Oates's intention was to benefit his companions, and not to die himself. QB replies: Oates accomplished his helping of the others by his own death. Since one must intend one's means, he intended his death.
I reply: Oats's death was not a necessary part of Oates's plan; it was his absence, or better, his non-use of the scarce resources, which was necessary, and this was accomplished by his walking away from camp (to certain death).
Similarly, the man who jumps out of an overladen life-boat, to lighten it, intends to lighten it, and to jump out (as a means to that), but does not (necessarily) intend his own death, which does nothing to advance his plan of saving the remaining people. (On this example see Henry Davis, Moral and Pastoral Theology.)
As a matter of fact, Oates is on record as advocating suicide using a revolver as a way out in these situations, and wanted a revolver on the expedition for the purpose. This would obviously involve the intention of death, since the only way shooting oneself brings about one's non-use of scarce resources is by one's being killed. This suggests Oates's intention may have been to kill himself. However this does not change the principles at work in the case.