Amplification and active imagination are especially characteristic of Carl Jung's work. Amplification is a method derived from philology. To decipher an obscure text philologists compare it with others whose content and meaning are known and which are sufficiently like the document under examination. The use of amplification in therapy depends upon the theory that the basis of the psyche is universal and that individuals need to be put in touch with this layer called the collective unconscious. By using amplification Jung aimed at mapping out characteristic features in the common basis of man's symbolic life, and constructing what might be called a geography of the psyche. Active imagination is a method of studying the self. It may take place spontaneously according to patterns starting in childhood, or it may be induced during analysis by concentrating on the archetypal imagery and urging the patient to treat it as real and objective.