During the height of the Roman Empire it became clear to ancient physicians that in order to better understand how natural systems work; they must be studied in their living states. That is, through the process of vivisection, from the Latin words vivus (living) and sectio (cutting), researchers would have to operate on living animals to provide insight on what was then a great empty field of physiology. The first focal figure in the field of vivisection was Galen of Rome (c. 130-201) personal physician to emperor Marcus Aurelius. Galen detailed procedures where he dissected living animals to obtain knowledge of the inner workings of the respiratory, nervous, and cardiovascular systems. Galen’s procedures pioneered the field of exploratory surgery, and he has consequently been dubbed the ‘father of vivisection’. It is important to note that Galen also made an effort to record both the physiological observations he made as well as the seemingly ‘unpleasant’ process performed on the subject.