241 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.
Source: Mater et Magistra (Vatican.va)