We must face the fact that society is founded on intolerance. There are glaring cases of the abuse of intolerance; but they are quite as characteristic of our own age as of the Middle Ages. The typical modern example and contrast is compulsory inoculation replacing what was virtually compulsory baptism. But compulsion to inoculate is objected to as a crudely unscientific and mischievous anti-sanitary quackery, not in the least because we think it wrong to compel people to protect their children from disease. Its opponents would make it a crime, and will probably succeed in doing so; and that will be just as intolerant as making it compulsory. Neither the Pasteurians nor their opponents the Sanitarians would leave parents free to bring up their children naked, though that course also has some plausible advocates. We may prate of toleration as we will; but society must always draw a line somewhere between allowable conduct and insanity or crime, in spite of the risk of mistaking sages for lunatics and saviors for blasphemers. We must persecute, even to the death; and all we can do to mitigate the danger of persecution is, first, to be very careful what we persecute, and second, to bear in mind that unless there is a large liberty to shock conventional people, and a well informed sense of the value of originality, individuality, and eccentricity, the result will be apparent stagnation covering a repression of evolutionary forces which will eventually explode with extravagant and probably destructive violence. Variability of Toleration.