Behaviorism has its roots as far back as the ancient Greeks. Hippocrates (460-377 BCE), known as the father of medicine, developed humorism consisting of four humors corresponding to four temperaments. Physicians and philosophers have used this model with its four temperaments for many years. Socrates (469-339 BCE), Plato (427-347 BCE), and Aristotle (385-322 BCE) are often spoken of together because of the unique relationship they have. common. Aristotle was a student of Plato, who was himself a student of Socrates, and it was their developments in philosophy, a precursor to modern psychology, that began to lay the foundations of what would one day become behaviorism. Socrates began by teaching the need to examine to know the truth and contributed greatly to the development of ethics. From here, Plato, a rationalist, expands by stating that one must turn away from sensation and concentrate on reasoning. By the time Aristotle took off, he had become an empiricist, a key part of what would become behaviorism. He is also recognized by many as the first scientist, a distinction that still exerts a clear influence on scientists today. Galen (129-217 CE), himself a physician and philosopher influenced by Hippocrates, became known as perhaps the greatest scientist. expert in medical knowledge of his time and of subsequent centuries. It is important to remember that for all his work in the medical field, Galen also considered himself a philosopher and, through his work in this and many other fields, today he is linked to behaviorism, just like Hippocrates, his teacher in a way. Descartes (1596-1650) was fascinated by Plato's rationalism, as well as his views on dualism. The idea that the mind and body interacted with each other...... middle of paper ......y. His development of the law of effect led to an expansion of behavioral theory in the sciences. Thorndike's operant conditioning, along with Pavlovian processes, has inspired the vast majority of behaviorist theory into the 21st century. Among these behaviorists, Watson (1870-1958) is considered the father, because it was he who founded the psychological school of behaviorism. His interest was strongly oriented towards observable behavior and the idea that such behavior was informed by past experience. Following in Watson's footsteps came Skinner (1906-1990) who, like Watson before him, created his own school of psychology called experimental behavior analysis. Within the psychological community, he is considered one of the great pioneering minds of behaviorism, alongside Pavlov and Watson. In 2002, Skinner was named the most influential psychologist of the 20th century..