It has been estimated that most of us do not utilize more than 10 percent of our mental capacity. Erickson certainly believes this. Our consciousness usually has too narrow, rigid, and limited a conception of what it is capable of accomplishing. Ordinary education and daily life have taught us how to accomplish some things but have unwittingly biased us against many if not most of our capacities.

We all know from everyday experience that we can be so absorbed in something that interests us that we ignore everything else. We can "not hear" someone calling us and we can "not feel" pangs of hunger. Yet if you baldly ask someone to "not hear" or "not feel," they will look at you in disbelief. Our normal consciousness does not know how to "not hear" or "not feel" on direct command, even though the mental apparatus can do these things easily and automatically when the everyday conditions of ordinary life are suitable. Milton Erickson's indirect forms of suggestion are all means of arranging such suitable conditions so that individuals can accomplish things that are within their behavioral repertory but usually not available to voluntary control (although automatically and unconsciously available when the ordinary circumstances of life call for them, as illustrated above).

The wonder and fascination of hypnosis is that it enables us to control these responses that are usually mediated by unconscious mechanisms outside the normal range of consciousness. The art and science of the hypnotherapist is in knowing enough about behavior and learning in general, and the individual experiences of each patient in particular, so the therapist can present suggestions to evoke all the responses necessary to accomplish a given therapeutic goal.

The theory is simple, but the practice is difficult until the therapist has really learned how to evoke responses that are usually outside the patient's normal range of ego control. There are vast individual differences to be taken into account. Some patients can easily accept direct suggestions simply because they believe so much in the therapist's "prestige" or "power." Such belief wipes away the limitations and doubts characteristic of their usual attitudes; they don't believe they can accomplish such and such by themselves, but their belief system allows them to accomplish it in the special circumstances of therapy. Other patients, more critical and doubting, caught in a narrow, rationalistic view of themselves, require indirect suggestions that will bypass the destructive limitations of their belief system. Still other patients, more in tune with the facts, recognize their personal limitations but need not believe in the prestige or power of the therapist; rather, they hope the therapist really has the skill to help them accomplish their goal by indirect suggestions whose rationale they need not understand at the time.