MENTAL EPIDEMICS 287
of fact the financial panic is a phenomenon which can ap pear in an intense form only in a rather highly organized system of national or international economy. It was simply impossible in a tribal or household system of economy. Strictly speaking, it seems that financial panics of a violent species are phenomena characteristic of the intermediate stages of economic organization on a national scale. They cannot occur until the financial system of the country has attained to a considerable degree of unity ; but as it develops it tends to become so highly centralized and integrated in some one great institution that each unit of the system is supported by the strength of the whole, and this gives a steadiness which inspires confidence and allays the excite ment which would lead to demoralization. When all the conditions are taken into consideration it is probable that mental epidemics of this variety, as of every other, are becoming more frequent, more diffusive and less violent. Assuming the truth of this contention, we may safely con clude that the general tendency is away from excessive and demoralizing, towards more moderate and healthy expe riences of this kind. We shall probably never witness again the wild insanities which from time to time afflicted society in the Middle Ages. It is not probable that such fanatical movements as the Crusades or such a madness as the anti- witchcraft mania will ever be possible again, nor should we except a repetition of such abnormal religious revivals as that which swept like wild-fire over the frontier population of Kentucky and Tennessee in 1800. This may be ac counted for by the general increase of intelligence, but the general increase of intelligence is itself coincident with and conditioned by the social processes so rudely sketched.
It is useless to argue as to the moral and social value of these abnormal religious excitements. Unquestionably some good results followed them, directly and indirectly; but it is also beyond dispute that these benefits were purchased at the cost of much injury. We have no scales in which we can weigh the good and ill effects ; but it is certain that the
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