Suggestion and Autosuggestion
According to the preceding remarks we can compare the imagination to a torrent which fatally sweeps away the poor wretch who has fallen into it, in spite of his efforts to gain the bank. This torrent seems indomitable; but if you know how, you can turn it from its course and conduct it to the factory, and there you can transform its force into movement, heat, and electricity.
If this simile is not enough, we may compare the imagination — "the madman at home" as it has been called — to an unbroken horse which has neither bridle nor reins. What can the rider do except let himself go wherever the horse wishes to take him? And often if the latter runs away, his mad career only comes to end in the ditch. If however the rider succeeds in putting a bridle on the horse, the parts are reversed. It is no longer the horse who goes where he likes, it is the rider who obliges the horse to take him wherever he wishes to go.
Now that we have learned to realize the enormous power of the unconscious or imaginative being, I am going to show how this self, hitherto considered indomitable, can be as easily controlled as a torrent or an unbroken horse. But before going any further it is necessary to define carefully two words that are often used without being properly understood. These are the words suggestion and autosuggestion.
What then is suggestion? It may be defined as "the act of imposing an idea on the brain of another". Does this action really exist? Properly speaking, no. Suggestion does not indeed exist by itself. It does not and cannot exist except on the sine qua non condition of transforming itself into autosuggestion in the subject. This latter word may be defined as "the implanting of an idea in oneself by oneself."
You may make a suggestion to someone; if the unconscious of the latter does not accept the suggestion, if it has not, as it were, digested it, in order to transform it into autosuggestion, it produces no result. I have myself occasionally made a more or less commonplace suggestion to ordinarily very obedient subjects quite unsuccessfully. The reason is that the unconscious of the subject refused to accept it and did not transform it into autosuggestion.