Some of those who think that St. James knew the Epistle to the Romans see here an allusion to the principle which St. Paul there lies down: "Whatsoever is not of faith is sin" (xiv. 23). For reasons already stated (p. 57), it must remain doubtful whether St. James had knowledge of that Epistle; and even if he had, we could not by any means be sure that he had it in his mind when he wrote the words before us. But his words and St. Paul's, when combined, give us a complete statement of a great moral principle respecting the possession or non-possession of knowledge as to what is right and wrong in any given case. So long as we have _no_ knowledge that a given act is right, _i.e._ so long as we are in doubt as to whether it is allowable or not, it is sin to do it. As soon as we _have_ knowledge that a given act is right it is sin to leave it undone. This principle cuts at the root of that unwholesome growth which in moral theology is known as the doctrine of _Probabilism_, and which has worked untold mischief, especially in the Roman Church, in which its chief supporters are to be found. This doctrine teaches that in all cases in which there is doubt as to whether a given act is allowable or not the less safe course may be followed, even when the balance of probability is against its being allowable, if only there are grounds for believing that it _is_ allowable. And some supporters of this doctrine go so far as to maintain that the amount of probability need not be very great. So long as it is not certain that the act in question is forbidden it may be permitted. The object of which teaching is not that which ought to be the object of all moral teaching, viz. to save beings with immortal souls from making serious mistakes of conduct, but to enable beings with strong desires and passions to gratify them without scruple. The moral law is not so much explained as explained away. The very titles of some of the treatises in which the doctrine of Probabilism is advocated indicate their tendency, _e.g._ "The Art of Perpetual Enjoyment."[83] To all such special pleading, and making the Word of God of none effect by human glosses, the simple principles laid down by St. Paul and St. James are the best antidote: "Whatsoever is not of faith is sin;" and "To him that knoweth to do good, and doeth it not, to him it is sin." [81] Horace, _Odes_ I. ix. 13. J. H. Newman, _Verses on Various Occasions_, "The Pillar of the Cloud," June 16th, 1833. [82] In commenting on Wisdom ii. 4, Farrar quotes Gregory Nazianzen: "We are a flitting dream, a phantom that cannot be grasped, the scud of a passing breeze, a ship that leaves no trace on the sea, dust, vapour, morning dew, a flower that now blossoms, and now is done away" (_Speaker's Commentary, Apocrypha_, I., p. 431).