In the last analysis, most of the ills of the body are rooted in some response to group activity. It will be necessary for us to grasp the fact that the phrase "group life and activity" must include not only past heredity, or inherited group tendencies, but also may indicate present world contacts, which weaken or increase resistance far more than is generally believed possible. One of the causes of cancer, which was not so prevalent in the earlier and more leisured [354] days of the racial life - for then the herd instinct was not so powerful as it is today - is due to the increased stimulation of the body. This stimulation is caused by our close contact in our daily lives with each other through our massed group existence, particularly in our urban centers. If cells are living organisms (which they are), they respond to group life, to massed cell emanation and radiation. This constant stream of energy pouring from the aggregate of bodily cells in massed humanity may produce in certain types of people an over-stimulation in some part of bodily cell structure. This usually occurs where there is a weakness in the etheric or vital body, which means that cell defenses are impaired and the result is frequently a cancer or a general cancerous condition. This is the fundamental cause, though modern investigation is occupied with secondary causes and effects of this etheric weakness. I shall consider this later in more detail. It will be obvious to you that when we begin to deal with the vital body and to consider it with greater understanding and knowledge, we shall be able to handle such diseases as cancer far more effectively.