No culture has yet been identified where the concept of conscience has not been recognised as central. The word ‘conscience’ was not always used: more common in early cultures were ‘heart’ and ‘loins’. Whatever the word used, the concept behind conscience pointed to the core of the human person. The lack of a consistent word for the concept of conscience has led to diverse explanations. Despite this, the concept of conscience has maintained a consistent reference to human freedom. Through freedom, the practical conduct of life was discerned, and humans were formed to live responsibly as individuals and within society.
The Bible has no specific term for conscience, but by the New Testament there is an emerging spirit which emphasises that conscience is to be distinguished from the legal obedience typical of Rabbinic writings. A person’s character and decisions are shaped by the heart and interior dispositions rather than by exterior obedience (cf. Mt 15:1-20, Lk 11:37-54). The insistence on purity of heart, under the caring eye of God, animates St Paul’s presentation of Christian conscience.