Pope Pius XI
December 31, 1929
58. Another grave danger is that naturalism which nowadays invades the field of education in that most delicate matter of purity of morals. Far too common is the error of those who with dangerous assurance and under an ugly term propagate a so-called sex-education, falsely imagining they can forearm youth against the dangers of sensuality by means purely natural, such as a foolhardy initiation and precautionary instruction for all indiscriminately, even in public; and, worse still, by exposing them at an early age to the occasions, in order to accustom them, so it is argued, and as it were to harden them against such dangers. Such persons grievously err in refusing to recognize the inborn weakness of human nature, and the law of which the Apostle speaks, fighting against the law of the mind; 43 and also in ignoring the experience of facts, from which it is clear that, particularly in young people, evil practices are the effect, no so much of ignorance of the intellect, as of weakness of a will exposed to dangerous occasions and unsupported by the means of grace.
59. In this extremely delicate matter, if, all things considered, some private instruction is found necessary and opportune from those who hold from God the commission to teach and who have the grace of state, every precaution must be taken. Such precautions are well known in traditional Christian education, and are adequately described by Antoniano, cited above, when he says: "Such is our misery and inclination to sin, that often in the very things considered to be remedies against sin we find occasions for and inducements to sin itself. Hence it is of the highest importance that a good father, while discussing with his son a matter so delicate, should be well on his guard and not descend to details, nor refer to the various ways in which this infernal hydra destroys with its poison so large a portion of the world; otherwise it may happen that, instead of extinguishing this fire, he unwittingly stirs or kindles it in the simple and tender heart of the child. Speaking generally, during the period of childhood it suffices to employ those remedies which produce the double effect of opening the door to the virtue of purity and closing the door upon vice."44
60. False also and harmful to Christian education is the so-called method of "co-education." This too, by many of its supporters, is founded upon naturalism and the denial of original sin, but by all, upon a deplorable confusion of ideas that mistakes a leveling promiscuity and equality for the legitimate association of the sexes. The Creator has disposed and ordained the perfect union of the sexes only in matrimony, and, with varying degrees of contact, in the family and in society. Besides, there is not in nature itself, which fashions the two quite different in organism, in temperament, in abilities, anything to suggest that there can be or ought to be promiscuity, and much less equality, in the training of the two sexes. These, in keeping with the wonderful designs of the Creator, are destined to compliment each other in the family and in society, precisely because of their differences, which therefore ought to be maintained and encouraged during their years of formation, with the necessary distinction and corresponding separation according to age and circumstances. These principles, with due regard to time and place, must, in accordance with Christian prudence, be applied to all schools, particularly in the most delicate and decisive period of formation, that, namely of adolescence; and in gymnastic exercises and deportment, special care must be had of Christian modesty in young women and girls, which is so gravely impaired by any kind of exhibition in public.
43. Romans 7:23.
44. Silvio Antoniano, Dell' educazione cristiana dei figliuoli (Turni, 1926), Bk. II, c. 88.