Intelligent Design Arguments vs. Nаturаlistic Evоlutiоn (Chаrles Darwin's theоry) Michael J. Behe is a theistic evolutionist. Behe, the author of Darwin's Black Box, is a biochemist who defines an "irreducibly complex system" as one that has interconnected parts that are all necessary for carrying out the particular function. In other words, if one part was missing from the system, the system would not work at all. All parts are necessary for it to work. What is his favorite example of an "irreducibly complex system" (found in Darwin's Black Box)?