Third, as a philosophical matter, an infertile marriage is fully a marriage. A marriage is a comprehensive union marked by one-flesh union—the coordination of the spouses’ two bodies toward the single biological end of reproduction. That coordination—and thus the one-flesh union—takes place whether or not it achieves its biological end in the fertilization of an egg by a sperm some hours later. The union, like the act that seals it, is still oriented toward family life. This explains why in common, civil, and canon law, infertility has never nullified a marriage.
