Explain the following concepts.
The word Psychology is derived from the Greek words 'Psyche' (meaning soul or mind) and 'Logos' (meaning science or branch of knowledge). Thus, the literal meaning of Psychology was 'science of the soul or science of the mind'. However, neither soul or mind can be described in concrete terms nor can be scientifically observed. Hence, the definition of Psychology was modified.
Wilhelm Wundt explained Psychology as the study of 'conscious experience'.
Sigmund Freud explained Psychology as the study of the unconscious and stressed the importance of early childhood experiences. However, neither consciousness nor 'Unconscious' are directly observable.
John Watson defined Psychology as 'a science of behaviour'.
Today, psychology is defined as, 'the scientific study of human behaviour and mental process'.