Any parent who stops to think at all can hardly feel happy in mind as to the way the average child has to acquire its first and most lasting impressions of the love by which God wishes the world to be populated.
The Holy Father himself has warned parents more than once in recent years that theirs is a positive duty to assist their children in this matter. And he has pointed out the danger of leaving a child to pick up I information "haphazard from some disturbing encounter, from secret conversations, through information received from over-sophisticated companions or clandestine reading."
He has stressed, moreover, that to learn of sex in a secretive way is far more dangerous to the child than if such information were to come from the parent; for unhealthy secrecy "inflames the imagination and troubles the senses."
There is, of course, a further consequence of indecent and inaccurate knowledge of sex - namely, a false and distorted attitude towards love itself that frequently perseveres, even after marriage, blighting the happiness both of husband and wife. Sex love is sacred quite independently of the fact that it was raised by Christ, Our Lord, to the dignity of a Sacrament. For, next to life itself, it is the most important thing that came from the hands of God. Not only is it the source of life for the child, but it is the basis of happiness and affection between the parents, and provides the atmosphere in which God wishes the child to be reared. It is in this that God has distinguished human love from the blind procreative instinct of the lower animals. On it hangs the eternal destiny of the human race. By it the family begins, and the home is made. Through it, and it alone, can heaven be filled.
No wonder, then, that there is uneasiness in the heart of every Catholic parent, who has young children yet to rear. For all around, this most sacred of God's gifts, is the object of filthy jokes and coarse suggestiveness. And they ask is it possible to forestall the desecration of the very idea of love in the hearts of their children before it occurs? Pius XII says "Yes - If imparted by the lips of Christian parents at the proper time, in the proper manner, and with the proper precautions, the revelation of the mysterious and marvelling laws of life will be received by them (the children) with reverence and gratitude."
- Malaya Catholic Newsletter, July 16, 1950 (1950.pdf pp18)