Actually this is more useful:
http://www.newadvent.org/cathen/01046b.htmHowever, if medical treatment or surgical operation, necessary to save a mother's life, is applied to her organism (though the child's death would, or at least might, follow as a regretted but unavoidable consequence), it should not be maintained that the fetal life is thereby directly attacked. Moralists agree that we are not always prohibited from doing what is lawful in itself, though evil consequences may follow which we do not desire. The good effects of our acts are then directly intended, and the regretted evil consequences are reluctantly permitted to follow because we cannot avoid them. The evil thus permitted is said to be indirectly intended.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
