Every once in a while, someone here links to one of several posts at EWTN Q&A which contains this claim:
Pope Pius XII put it in this way: “Marriage is a mutual commitment in which each side ceases to be autonomous, in various ways and also sexually: the sexual liberty in agreement together is great; here, so long as they are not immoderate so as to become slaves of sensuality, nothing is shameful, if the complete acts - the ones involving ejaculation of the man’s seed - that they engage in are true and real marriage acts.” Pope Pius XII addressed these matters in his "Address to the Second World Congress on Fertility and Sterility, "
That quote is actually from G.E.M. Anscombe; she’s a British analytic philosopher. The quote is from her article “Contraception and Chastity”
What Pope Pius XII actually taught at the Second World Congress on Fertility and Sterility is essentially the opposite to what the quote says. He limits the full use of the sexual faculty by the man or by the woman solely to the natural marital act itself. Here is the full Address:
paragraphs 22 - 25 are at issue