A subject such as this is much too large to deal with at all fully in a short paper. As it is designed as a preparatory review of this topic as it applies to Great Britain, the subject being dealt with at the International Congress of Mental Health by delegates from overseas, I am placing the emphasis on the community rather than on the aggressive child. It is necessary, however, to consider what the aggressive child does to the community and why, in addition to discussing what the community does to the aggressive child, and the reason for this.