In verse 15, the case was supposed of a brother's being grieved by what he felt to be laxity. That case corresponded to the stumbling-block of verse 13. A worse result seems contemplated in verse 20,--that of the weak brother, still believing that laxity was wrong, and yet being tempted by the example of the stronger to indulge in it. In that event, the responsibility of overthrowing what God had built lies at the door of the tempter. The metaphor of 'overthrowing' is suggested by the previous one of 'edifying.' Christian duty is mutual building up of character; inconsiderate exercise of 'liberty' may lead to pulling down, by inducing to imitation which conscience condemns. From this point onwards, the Apostle first reiterates in inverse order his two broad principles, that clean things are unclean to the man who thinks them so, and that Christian obligation requires abstinence from permitted things if our indulgence tends to a brother's hurt. The application of the latter principle to the duty of total abstinence from intoxicants for the sake of others is perfectly legitimate, but it is an application, not the direct purpose of the Apostle's injunctions. In verses 22 and 23, the section is closed by two exhortations, in which both parties, the strong and the weak, are addressed. The former is spoken to in verse 22, the latter in verse 23. The strong brother is bid to be content with having his wider views, or 'faith'--that is, certainty that his liberty is in accordance with Christ's will. It is enough that he should enjoy that conviction, only let him make sure that he can hold it as in God's sight, and do not let him flourish it in the faces of brethren whom it would grieve, or might lead to imitating his practice, without having risen to his conviction. And let him be quite sure that his conscience is entirely convinced, and not bribed by inclination; for many a man condemns himself by letting wishes dictate to conscience. On the other hand, there is a danger that those who have scruples should, by the example of those who have not, be tempted to do what they are not quite sure is right. If you have any doubts, says Paul, the safe course is to abstain from the conduct in question. Perhaps a brother can go to the theatre without harm, if he believes it right to do so; but if you have any hesitation as to the propriety of going, you will be condemned as sinning if you do. You must not measure your corn by another man's bushel. Your convictions, not his, are to be your guides. 'Faith' is used here in a somewhat unusual sense. It means certitude of judgment. The last words of verse 23 have no such meaning as is sometimes extracted from them; namely, that actions, however pure and good, done by unbelievers, are of the nature of sin. They simply mean that whatever a Christian man does without clear warrant of his judgment and conscience is sin to him, whatever it is to others. TWO FOUNTAINS, ONE STREAM