But we are able to carry the conjecture a step beyond this. Here I am glad to avail myself of the criticism of Professor Westermarck, who has pointed out that a semi-supernatural character is very generally ascribed to strangers, and that intercourse with a stranger would thus be productive of blessings--especially the blessing of fertility--to the woman.[285.1] From the large collections on the subject of relations with strangers brought together by Professor Frazer and Professor Westermarck himself it results that a stranger is regarded as uncanny. He is a being possessed of unknown powers for good or ill. His _orenda_, as we have seen, is incalculable.[285.2] He must therefore be either repulsed at once as a foe or received and treated with extraordinary respect. The former course is not usually adopted unless the strangers come in force or there are other circumstances that suggest hostile intent. The latter course has given birth to laws of hospitality recognized all over the world, however the exact procedure may differ among different peoples. {286} But even in this case the stranger is looked upon with suspicion until he has undergone what M. van Gennep calls rites of aggregation to the group or society to which he has come. These rites may be of the most simple character, such as spitting upon his host or drinking a cup of water or coffee from his host’s hand; or they may involve a trial of strength, an exchange of gifts, the offering of sacrifices or entry into a blood-covenant.[286.1]