obliged to explain the surprising fact that under a certain condition this individual whom it had come to understand thought, felt, and acted in quite a different way from what would have been expected. And this condition is his insertion into a collection of people which has acquired the characteristic of a 'psychological group'. What, then, is a 'group'? How does it acquire the capacity for exercising such a decisive influence over the mental life of the individual? And what is the nature of the mental change which it forces upon the individual?
It is the task of a theoretical Group Psychology to answer these three questions. The best way of approaching them is evidently to start with the third. Observation of the changes in the individual's reactions is what provides Group Psychology with its material; for every attempt at an explanation must be preceded by a description of the thing that is to be explained.
I will now let Le Bon speak for himself. He says: 'The most striking peculiarity presented by a psychological group[1] is the following. Whoever be the individuals that compose it, however like or unlike be their mode of life, their occupations, their character, or their intelligence, the fact that they have been transformed into a group puts them in possession of a sort of collective mind which makes
- ↑ [See footnote page I.]
