This paper deals with the clinical appearance of depersonalization and 'derealization', and it analyzes the interrelationship between time, reality, and purpose. The sense of time develops in connection with repetitive bodily stimuli ('intrasomatic acquisition of the sense of time') and is maintained by a sufficiently strong appreciation of reality which, in turn, is dependent upon the amount of feeling towards the body and the outer world. The sense of reality is strengthened by purposive strivings, but purpose will always be weak if reality appreciation is disturbed. As illustrated by a psychoanalytic history, purposes in life and the appreciation of time are dependent upon the type of superego. Depersonalization ('a loss of emotional investment in the ego which may occur psychologically as a result of long continued repression of an aggressive emotion, such as hate') is always accompanied by a distorted sense of time, ultimately by timeless living.