417. Is such a law perceived by everyone?

417. Is such a law perceived by everyone?   

(Comp 417) Because of sin the natural law is not always perceived nor is it recognized by everyone with equal clarity and immediacy. For this reason God “wrote on the tables of the Law what men did not read in their hearts.” (Saint Augustine)

“In brief”

(CCC 1981) The Law of Moses contains many truths naturally accessible to reason. God has revealed them because men did not read them in their hearts.   

To deepen and explain

(CCC 1960) The precepts of natural law are not perceived by everyone clearly and immediately. In the present situation sinful man needs grace and revelation so moral and religious truths may be known "by everyone with facility, with firm certainty and with no admixture of error" (Pius XII, Humani generis: DS 3876; cf. Dei Filius 2: DS 3005) The natural law provides revealed law and grace with a foundation prepared by God and in accordance with the work of the Spirit. 

Reflection

(CCC 2071) The commandments of the Decalogue, although accessible to reason alone, have been revealed. To attain a complete and certain understanding of the requirements of the natural law, sinful humanity needed this revelation: A full explanation of the commandments of the Decalogue became necessary in the state of sin because the light of reason was obscured and the will had gone astray (St. Bonaventure, Comm. sent. 4, 37, 1, 3). We know God's commandments through the divine revelation proposed to us in the Church, and through the voice of moral conscience.   

(Next question: What is the relationship between the natural law and the Old Law?)