Patients undergoing hypnosis are free subjects in the sense that they possess a particular dignity and entitlement to respect. They are, in fact, "not available" for examination except insofar as there is an expected or auspicable improvement in their personal condition. This means that they are open to "experiment" solely to the extent that the following conditions are respected: certain control if situations involving risk to the person arise, "consent" of the patient (this may be only assumed in certain instances), the adoption of a "prudent" and "scientific" manner that avoids any suggestion of a spectacle or cheap publicity.