The human brain is an excellent memory mechanism. To turn it into a "thinking" mechanism, appropriate programs are needed. In this book, which can be considered a textbook on such "software", Edward de Bono proposes a thinking technique consisting of five stages. You will learn to concentrate your attention on the subject of reflection, since the effectiveness of thinking depends on this. Instead of conventional, disordered thinking, the author suggests five clearly defined stages. A simple coding system indicates where maximum effort needs to be made. At each stage, tools are offered to simplify mental operations. Edward de Bono's technique is based on many years of practical experience and is quite easy to use.