Thus I cannot hold with Mr. Jevons that the human mind is provided with an _a priori_ categorical imperative that there are some things which must not be done,' 'a feeling' 'independent of sense experience.'[4] If the choice of what things are 'not to be done' seems to us 'irrational,' that is merely because our reason is more enlightened than that of the savage. He prohibited just such things as his philosophy, and what he believed to be his experience, showed him to be dangerous for obscure reasons. Any fool could see that it was dangerous to eat poison berries or frolic with a bear. But it took reflection to discover that a baby or a corpse was dangerous by reason of evil spirits, _Iruntarinia_, whom the _Alkna Buma,_ or clairvoyant, could see, and describe, though Mr. Jevons and I could not discern them.[5] These Iruntarinia notoriously carry off women, and probably, like the fairies, have their best chance in the hour of child-birth: at all events, the fairies have.[6] The belief is socially useful: it prevents young Arunta women from wandering off alone, and philandering out of bounds. Thus these taboos are sanctioned by the tribal counsellors as the results of experience, not their own perhaps, but that of the _Alkna Buma_, or clairvoyant, or 'sensitive,' or 'medium,' or habitually hallucinated person. Other taboos, as to women, are imposed for very good reasons, though not for the reasons alleged, and broken taboos are not (in actual ordinary experience) attended by the penalties which, however, suggestion may produce. Taboo, then, is not imposed irrationally, nor in deference to 'an inherent tendency of the human mind' (that Mrs. Harris of philosophy), but for a very good reason, as savage reasoning goes, and in accordance with what is believed to be experience, and, by dint of suggestion, really does become experience. It was 'irrational' in Dr. Johnson to touch certain posts, and avoid certain stones, and enter a door twice, if he first entered it with the wrong foot. All my life I have had similar private taboos, though nobody knows better that they are nonsense. But some solitary experience in childhood probably suggested a relation of cause and effect, where there was only a fortuitous sequence of antecedent and consequent, and so Dr. Johnson and I (though not so conspicuously as the Doctor) imposed taboos on ourselves in deference to (fancied) experience. Early man has acted in the same way on a large scale, obeying no categorical _a priori_ imperative, but merely acting on his philosophy and experience which is real to him, though not to civilised men. They usually do not understand it, but educated persons with a survival of savagery in their mental constitutions find the affair intelligible.