It is in this sense of a self-judging faculty in all men reflecting on what they have done, anticipating a divine { 209} judgement, that the idea of conscience was acclimatized among the Jews. Thus, in Wisdom xvii. 11, we read, 'For wickedness, condemned by a witness within, is a coward thing, and being pressed hard by conscience, always forecasteth the worst lot.' In St. John viii. 9, according to one reading, the Jews are 'convicted by their own conscience.' So St. Paul, in the passage discussed above (ii. 15), seems to distinguish the subsequent reflective 'conscience' from the previous informing reason, 'the effect (equivalent) of the law written in their hearts.' And in most of the passages of the New Testament, this meaning of conscience--the faculty by which we sit in judgement on what we have already done--is sufficient. But sometimes, as also among the Stoics[3], the word passes into meaning the positive directing faculty, as when (1 Cor. viii. 10) a man's 'conscience' is said to be 'emboldened' to adopt a new practice, or (Hebr. ix. 14) to be cleansed for positive service. Moreover, though it is an individual faculty (see Rom. ii. 15), and exists primarily to pass judgement on one's own actions only, yet perforce it must also look without and condemn or approve the actions of others (2 Cor. iv. 2, v. 11).
St. Paul also brings into notice that our conscience is a faculty for the condition of which we are responsible. It is not the voice of God, but a faculty capable of reflecting His voice, if it be well guarded. Thus you may have a 'weak' or a 'strong,' i.e. a more or less enlightened, conscience (1 Cor. viii). And a man may 'defile' his 'mind and conscience,' i.e. he may corrupt his moral reason and powers of moral self-judgement (Tit. i. 15). { 210} Then the 'conscience' may become hardened and 'seared' (1 Tim. iv. 2), so that 'the light that is in' men becomes itself 'darkness' according to our Lord's warning (St. Matt. vi. 23). And there is nothing which is more necessary at the present day than to remind men that they are not 'safe' because they are not acting against their conscience, unless they are also constantly at pains to enlighten their conscience and keep it in the light, by the help of the best moral thought of their time, the guidance of the Church and the word of God. Our conscience, if it is rightly to reassure us by its witness, must, like St. Paul's conscience, bear its witness 'in the Holy Ghost' (Rom. ix. 1).