Ubi Arcano Dei Consilio §16

¹⁶ We wish to record, in addition to the evils already mentioned, other evils which beset society and which occupy a place of prime importance but whose very existence escapes the ordinary observer, the sensual man - he who, as the Apostle says, does not perceive "the things that are of the Spirit of God" (I Cor . ii, 14), yet which cannot but be judged the greatest and most destructive scourges of the social order of today. We refer specifically to those evils which transcend the material or natural sphere and lie within the supernatural and religious order properly so-called; in other words, those evils which affect the spiritual life of souls. These evils are all the more to be deplored since they injure souls whose value is infinitely greater than that of any merely material object.