Hippocrates (460–370 BCE) – The Father of Medicine Approach: Humoral Theory (Balance of bodily fluids affecting personality and behavior) Examples: Plato (427–347 BCE) – The Philosopher-Psychologist Approach: Dualism (Mind and body are separate) Examples: Aristotle (384–322 BCE) – The First Empirical Psychologist Approach: Empirical Observation and Associationism Examples: Galen (129–216 CE) – Early Psychophysiologist Approach: