Structuralism was formed out of the necessity to distinguish psychology as a science separate of philosophy and/or biology. Functionalism came out of opposition to the basic premises of structuralism. Major differences among functionalism and structuralism are in the ideas of how the mind is organized. Functionalism viewed the mind by how it functioned rather than how it was structured (Schultz, D. P., & Schultz, S. E., 2008). Structuralism looked at mental processes through analysis and description and functionalism through behavior (i.e., how and why people behaved). Functionalism explored how the mind changed based on experiences and environment. The basic premise of functionalism is still seen in modern psychology. Darwin a major theorist in functionalism introduced the idea of, “Evolution”. He proved that the mind evolved/s over time (Schultz, D. P., & Schultz, S. E., 2008). Darwin focused on, “Animal psychology to form a basis comparison, placed emphasis on functions rather than the structure of consciousness, accepted methodology and data from many fields, and focused on description and measurements of individual differences (Schultz, D. P., & Schultz, S. E., 2008 p. 155).” A significant portion of the initial premises Darwin established are in practice in modern psychology through the theories that emerged following functionalism.