a practice which would now be sanctioned. The fact can neither be denied nor ignored that these same acts would now be declared licit on the grounds of principles cited by the Protestants, which popes and bishops have either condemned or at least not approved. It is said that none of the instances cited falls under the domain of papal infallibility; the Pope is not considered infallible except in the rare, solemn occasions when he is speaking ex cathedra. According to M. R. Gagnebet, though the encyclical Humanae vitae is considered by some to be a non-infallible document, "the doctrinal authority of the Pope and the Bishops is not limited to infallible teaching. The duty of obedience is not restricted to definitions of faith". Theological opposition has come from some denominations of Protestant Christianity. The Reformed theologian John Piper's Desiring God ministry states of NFP, "There is no reason to conclude that natural family planning is appropriate but that 'artificial' (non-abortive) means are not." Eastern Orthodox couple Sam and Bethany Torode, former advocates of NFP-only, have redacted their position to include barrier methods and explain their current theology this way: We also see honest congruity with the language of the body by saying "no" to conception with our bodies (via barrier methods or sensual massage) when our minds and hearts are also saying "no" to conception. We don't believe this angers God, nor that it leads to the slippery slope of relativism or divorce. We strongly disagree with the idea that this is a mortal sin.... It's a theological attack on women to always require that abstinence during the time of the wife's peak sexual desire (ovulation) for the entire duration of her fertile life, except for the handful of times when she conceives. Traditionalist Catholic priest Francis Ripley criticizes the concept: See also Fertility monitor Billings ovulation method Calendar-based contraceptive methods Catholic teachings on sexual morality Couple to Couple League New feminism Theology of the Body References Further reading Moral Use of Natural Family Planning (PDF). Prof. Janet E. Smith (Moral Theologian and Public Speaker). B.A., M.A., Ph.D., School of Theology, Fr. Michael J. McGivney Chair in Life Ethics, Professor of Moral Theology. At SHMS 2001–present. External links Catholic theology of the body Christian terminology Fertility awareness Family planning de:Empfängnisverhütung#Natürliche Methoden