But before attempting to survey the special {110} facts that present themselves within these three departments, it is well to note one phenomenon that concerns religion and morality in equal measure, and is of perhaps greater importance than all others in the varied process of the evolution of the cathartic idea. We have mainly been dealing so far with facts that seem to belong to the most primitive deposit of human consciousness and not properly to be ethical in the modern sense at all: the stain of blood, even incurred by ruthless murder, the stain of childbirth and the sexual processes, the contagion of the corpse, are all for the same reason “suspect” to primitive man because they involve vague and mysterious danger, not because they are associated with the concept of sin. Nor does this latter concept necessarily enter in, even when a more articulate animism has taken possession of the superstition, and the impurity means the presence of an evil spirit: the leper, the man who has come into contact with the dead, {111} the blood-stained murderer, are all regarded as suffering from the same trouble, though in greater or lesser degree. The idea of purity and impurity, in fact, whether corporeal and external or whether spiritual in the sense of its association with the world of spirits, is still non-ethical, and we must not apply our moral standards to it until a later stage. It arrives at this stage and at its higher significance for morality when it has evolved the conception of a pure heart, a pure soul. And that this latter, which is one of the most pregnant of the concepts of developed ethics, was actually evolved from the primitive ritualistic and demoniac superstition can, I believe, be proved by the evidence, and accords with a well-known psychologic law of early thought.