187-WATCH lest you be too hasty to judge the failure or success of demonstration by its human manifestation. That which would mark a demonstration of protection as successful, might denote failure in a demonstration that was intended to be an aggressive attack on error, in order to expose and destroy it. The manifestation of a protective demonstration might be temporary human harmony, in contrast to the manifestation of a demonstration intended to overthrow error. The chemicalization produced by the latter might bring out temporary human discord, as the muddy river bed is being stirred. On pages 96 and 540 of Science and Health Mrs. Eddy describes the temporary discord following the demonstration of exposing and destroying error. Nehemiah 6:3 describes the demonstration of protection,-the building of the wall,-that must precede the aggressive warfare against error. Mrs. Eddy once said, "We must not rely too much on the thought, 'By their fruits shall ye know them.' " Perhaps she said this to prevent beginners, who were making the demonstration of protection, from criticizing advanced students, who were making the demonstration of destroying error, and who, therefore, would not always manifest the harmony beginners think they should. The latter may fancy that the former are failing in demonstration, because they do not manifest a continuous peace in matter or material sense, when such is not the case. This criticism, carried out logically, would mark Jesus' crucifixion as a failure in demonstration. It would cause many of our Leader's experiences to be branded as failures, in which she found herself assailed by arguments of discord, because she was exposing and destroying hidden sin. On page 92 of Science and Health we read, "Uncover error, and it turns the lie upon you."