Psychology is the scientific study of behaviour and mental processes.
It asks and tries to answer questions about every aspect of life. Laws and public policy are influenced by psychologists theories and research. In the 4th and 5th centuries B.C Socrates, Plato and Aristotle were Greek philosophers who posed fundamental questions about mental life. These questions are considered the roots of a cognitive perspective of psychology. At the same time Hippocrates' observations of the brain controlling the rest of the body led to biological explainations.