Verse 41 teaches that the accurate measurement of the magnitude of our own failings should precede our detection of our brother's. Christ assumes the commonness of the opposite practice by asking 'why' it is so. And we have all to admit that the assumption is correct. The keenness of men's criticism of their neighbour's faults is in inverse proportion to their familiarity with their own. It is no unusual thing to hear some one, bedaubed with dirt from head to foot, declaiming with disgust about a speck or two on his neighbour's white robes. Satan reproving sin is not an edifying sight, but Satan criticising sin is still less agreeable. If only 'he that is without sin among you' would fling stones, there would be fewer reputations pelted than there are. Most men know less about their own faults than about their brother's. They use two pairs of spectacles--one which diminishes, and is put on for looking at themselves; one which magnifies, and is worn for their neighbour's benefit. But when their respective good qualities are to be looked at, the other pair is used in each case. That is men's way, all the world over. Christ's question asks the reason for this all but universal dishonesty of having two weights and measures for faults. He would have us ponder on the cause, that we may discover the remedy. He would have us reflect, that we may get a vivid conviction of the unreasonableness of the practice. There is nothing in the fact that a fault is mine which should make it small in my judgment; nor, on the other hand, in the accident that it is another's, which should make it seem large. A fault is a fault, whoever it belongs to, and we should judge ourselves and others by the same rule. Only we should be most severe in its application to ourselves, for we cannot tell how much our brother has had, to diminish the criminality of his sin, and we can tell, if we will be honest, how much we have had, to aggravate that of ours. So the conscience of a true Christian works as Paul's did when he said 'Of whom I am chief,' and is more disposed to make its own motes into beams than to censure its brother's. The reason, so far as there is a reason, can only lie in our diseased selfishness, which is the source of all sin. And the blindness to our 'beams' is partly produced by their very presence. All sin blinds conscience. A man with a beam in his eye would not be able to see much. One device of sin, practised in order to withdraw the doer's attention from his own deed, is to make him censorious of his fellows, and to compound for the sins he is inclined to by condemning other people's.