Intolerance is almost inevitably accompanied by a natural and true inability to comprehend or make allowance for opposite points of view. The skilled scientist who may be receptive to any promising suggestion in his own field may outside of his own field be found quite unwilling to make any attempt at understanding a point of view contrary to his own. In politics, for example, his understanding of the problem may be fragmentary, yet he will enter excitedly into discussions on bonus and ship subsidy, of which he has made no study. We find here with significant uniformity what one psychologist has called “logic-proof compartments.” The logic-proof compartment has always been with us. Scientists have lost their lives through refusing to see flaws in their theories. Intelligent mothers give food to their babies that they would manifestly forbid other mothers to give their children. Especially significant is the tendency of races to maintain religious beliefs and customs long after these have lost their meaning. Dietary laws, hygienic laws, even laws based upon geographical conditions that have been changed for more than a thousand years are still maintained in the logic-proof compartment of dogmatic adherence. There is a story that certain missionaries give money to heathen at the time of conversion and that the heathen, having got their money, bathe away their conversion in sacred streams. The characteristic of the human mind to adhere to its beliefs is excellently summarized in the volume by Mr. Trotter to which reference has been made before. “It is clear,” says Mr. Trotter,[5] “at the outset that these beliefs are invariably regarded as rational and defended as such, while the position of one who holds contrary views is held to be obviously unreasonable.