Psychology is the scientific study of the mind and behavior, including both conscious and unconscious phenomena like feelings and thoughts. The word psychology comes from the Greek words meaning "breath, principle of life, soul" and "speech, word, reason". Wilhelm Wundt is considered the father of modern psychology, establishing psychology as a science in the late 19th century. Some major theories and approaches in the history of psychology include structuralism, functionalism, Gestalt psychology, behaviorism, psychoanalysis, humanism, and cognitive psychology. School psychology applies psychological principles to education by addressing issues like assessment, testing, and student consultation in schools.