The personal unconscious is an unnecessary department of the mind. It is not a natural and inherited equipment, but a department created subsequent to birth by the mistakes of education. This chapter describes the technique aimed at repairing in the adult the evils consequent upon a defective education in childhood. The misuse of conscious activities resulting from inherited habits and defective training has been described by Mr. F. Matthias Alexander, who has also devised and successfully practised for over thirty years a technique for improving conscious activity by re-education. An essential feature of Mr. Alexander's teaching is his insistence that mind and body are not two separate fields of activity but one and indivisible. Every physical act is the result of a mental direction, and every thought is an activity of the physical brain. Wrong usage of the body, therefore, also impairs the mind, and correct usage leads to improved mental as well as bodily activity.