In performing this task, which is a noble one, they must not only be well qualified in their trade or profession and practice it in accordance with its own proper laws, they must also bring their professional activity into conformity with the Church's social teaching. Their attitude must be one of loyal trust and filial obedience to ecclesiastical authority. They must remember, too, that if in the transaction of their temporal affairs they take no account of those social principles which the Church teaches, and which We now confirm, then they fail in their obligations and may easily violate the rights of others. They may even go so far as to bring discredit on the Church's teaching, lending substance to the opinion that, in spite of its intrinsic value, it is in fact powerless to direct men's lives.
As We have noted already, modern man has greatly deepened and extended his knowledge of nature's laws, and has harnessed the forces of nature, making them subservient to his ends. The magnitude of his achievements deserves ungrudging admiration; nor is he yet at the end of his resources. Nevertheless, in his striving to master and transform the world around him he is in danger of forgetting and of destroying himself. As Our Predecessor, Pope Pius Xl, lamented in Quadragesimo Anno: "And so bodily labor, which even after original sin was decreed by Providence for the good of man's body and soul, is in many instances changed into an instrument of perversion; for from the factory dead matter goes out improved, whereas men there are corrupted and degraded." 48AAS 23 (1931) 221 et seq.
Similarly, Our Predecessor, Pius XII, rightly asserted that our age is marked by a clear contrast between the immense scientific and technical progress and the fearful human decline shown by "its monstrous masterpiece . . . transforming man into a giant of the physical world at the expense of his spirit, which is reduced to that of a pygmy in the supernatural and eternal world." 49Broadcast message, Christmas Eve, 1953; cf. AAS 46 (1954) 10.