Natural family planning is not a form of contraception as the Church has always understood it. In Humanae Vitae, in line with the long tradition of Christian reflection on the subject, Pope Paul VI defined contraception as an action performed before, during, or after an act of sexual intercourse with the intent to render that act of intercourse sterile when it might otherwise be fertile. NFP does not fit the bill. It does not represent an attempt to render infertile what one supposes might otherwise be a fertile sexual act. Whatever one’s moral judgment about NFP, it cannot be said to involve the sterilizing of sex acts. It is true that NFP can be practiced with a “contraceptive mentality.” That occurs, for example, when someone who would be perfectly willing to contracept chooses periodic abstinence because it is less unpleasant, more convenient, more effective (where reliable contraceptives are not to hand and only unreliable contraceptive techniques are available), or for other such reasons. I join Michael P. in suggesting that folks who are interested in the question of the morality of contraception and the question of whether NFP is properly understood as “relativizing the procreative norm,” do a bit of reading on the subject. Michael has recommended Sr. Margaret Farley’s book Just Love: A Framework for Christian Sexual Ethics. I say, by all means, read it. I would also suggest reading Elizabeth Anscombe’s four essays on contraception (including her classic “Contraception and Chastity”) reprinted in Mary Geach and Luke Gormally (eds.), Faith in a Hard Ground: Essays on Religion, Philosophy and Ethics by G.E.M. Anscombe (Imprint Academic, 2008); John Finnis’s “The Good of Marriage and the Morality of Sexual Relations: Some Philosophical and Historical Observations,” The American Journal of Jurisprudence 42 (1997) 99-134; and his, “Marriage: a Basic and Exigent Good,” The Monist 91 (2008); and Germain Grisez, The Way of the Lord Jesus, vol. 2, Living a Christian Life (Franciscan Press, 1993), chap. 9, together with the pertinent comments by Germain Grisez M. Boyle, Jr. in “Response to Our Critics & Our Collaborators,” in Robert P. George (ed.), Natural Law & Moral Inquiry: Ethics, Metaphysics & Politics in the Work of Germain Grisez (Georgetown UP, 1998).