In psychology, the psyche is the totality of the human mind, conscious and unconscious. Many thinkers, including Carl Jung, also include in this definition the overlap and tension between the personal and the collective elements in man. Psychology is the scientific or objective study of the psyche. The word has a long history of use in psychology and philosophy, dating back to ancient times, and represents one of the fundamental concepts for understanding human nature from a scientific point of view. The English word soul is sometimes used synonymously, especially in older texts. Etymology The basic meaning of the Greek word ψυχή (psyche) was "life", although unsupported, some have claimed it is derived from the verb ψύχω (psycho, "to blow"). Derived meanings included "spirit", "soul", "ghost", and ultimately "self" in the sense of "conscious personality" or "psyche". Ancient psychology The idea of the psyche is central to the philosophy of Plato. Scholars translate the Platonic conceptualization of the term as "soul" in the sense that he believed that it is immortal. In his Phaedo, Plato has Socrates give four arguments for the immortality of the soul and life after death following the separation of the soul from the body. Plato's Socrates also states that after death the Psyche is better able to achieve wisdom and experience the Platonic forms since it is unhindered by the body. The Greek philosopher Aristotle wrote an influential treatise on the psyche, called in Greek (Peri Psyches), in Latin De Anima and in English On the Soul. In this work, he used the concept of the soul to explain certain functions. Since - for him - the soul is motion, it needs an explanatory principle for bodily motion. Aristotle's theory of the "three souls (psyches)" (vegetal, animal, and rational) would rule the field of psychology until the 19th century. Prior to Aristotle, a number of Greek writings used the term psyche in a less precise sense. In late antiquity, Galenic medicine developed the idea of three "spirits" (pneuma) corresponding to Aristotle's three souls. The pneuma psychikon corresponded to the rational soul. The other two pneuma were the pneuma physicon and the pneuma zoticon. Medieval psychology The term psyche was Latinized to anima, which became one of the basic terms used in medieval psychology. Anima would have traditionally been rendered in English as "soul" but in modern usage the term "psyche" is preferable. Phenomenology 19th century