And if it once has been, it always will be: not that he thinks of it in this general way. But even animals, as soon as they have learnt a sequence, trust to it. Dogs and cats learn faster than guinea-pigs; monkeys faster than dogs and cats; man quicker still. But in no case would there be any use in learning, if it did not lead to action as if the experience had been generalised. There is no mystery in generalisation; it is spontaneous, and only waits for language to express itself; the difficult thing to acquire is caution. In default of method, the only test of truth is relative constancy in experience—_per enumerationem simplicem_—faulty but broadly effective; which requires time and practice. Primitive Magic is an incautious, unexpressed generalisation; and the conditions are such that the error cannot be easily detected. As long as a savage follows the instinctive, traditionary and acquired knowledge that he has of hunting, practices based on wrong judgments, but not interfering with the traditionary art, such as the carrying about of a bone, or a crystal, or having a special pattern on his quiver, cannot impair his success; may add to it by increasing his confidence: so that as long as success lasts there is nothing to suggest the falsity of the judgment. A series of failures may make the hunter throw away his talisman, or (at a later stage of Magic) take it to a medicine-man to be redoctored. How many thousands of times may Magic have begun in this way and lost its hold again, before the human mind became chronically infected with it! Similarly with amulets, anything unusual that a man happens to have about him, when attacked by a leopard or snake, from which he escapes, may be kept as a safeguard against future perils. And with rites: any gesture or action, however irrelevant, that happens to precede a successful effort, may be repeated in order to reinstate all the antecedents of success. So, too, with the origin of spells. It is a common impulse, and quite spontaneous, to accompany an action with words, incentive or expletive. If a hunter does so in driving home his spear successfully, he will next time repeat the words: they then become a spell.[106] First, then, there are practices of carrying about charms, repeating words, repeating actions; next, along with these practices, beliefs grow up as to the nature of their efficacy, their virtue; and much later it is discovered that some of the practices seem to involve certain common principles which the savage had never thought of.