Of the several kinds of crowds, I have selected for our discussion the mass meeting, because we are primarily interested in the _ideas_ which dominate the crowd. The same essential psychological elements are also found in the street crowd or mob. Serious mob outbreaks seldom occur without mass meetings, oratory, and propaganda. Sometimes, as in the case of the French Revolution and of the rise of the Soviets in Russia, the mass meetings are held in streets and public places. Sometimes, as, for instance, the crowds in Berlin when Germany precipitated the World War, a long period of deliberate cultivation of such crowd-ideas as happen to be advantageous to the state precedes. There are instances, such as the Frank case, which brought unenviable fame to Georgia, when no mass meeting seems to have been held. It is possible that in this instance, however, certain newspapers, and also the trial--which, as I remember, was held in a theater and gave an ambitious prosecuting attorney opportunity to play the role of mob leader--served the purpose of the mass meeting. The series of outbreaks in New York and other cities, shortly after the War, between the socialists and certain returned soldiers, seem to have first occurred quite unexpectedly, as do the customary negro lynchings in the South. In each case I think it will be found that the complex of crowd-ideas had been previously built up in the unconscious. A deep-seated antagonism had been unconsciously associated with the self-appreciative feelings of a number of individuals, all of which found justification in the consciousness of these persons in the form of devotion to principle, loyalty, moral enthusiasm, etc. I suspect that under many of our professed principles there lurk elements of unconscious sadism and masochism. All that is then required is an occasion, some casual incident which will so direct the attention of a number of these persons that they provide one another temporarily with a congenial social environment. In the South this mob complex is doubtless formed out of race pride, a certain unconscious eroticism, and will to power, which unfortunately has too abundant opportunity to justify itself as moral indignation. With the returned soldiers the unconscious desires were often rather thinly disguised--primitive impulses to violence which had been aroused and hardly satisfied by the war, a wish to exhibit themselves which found its opportunity in the knowledge that their lawlessness would be applauded in certain influential quarters, a dislike of the nonconformist, the foreign, and the unknown, which took the outward form of a not wholly unjustifiable resentment toward the party which had to all appearances unpatriotically opposed our entrance into the war.