Hippocrates and Hippocratic medicine The Hippocratic Corpus contains the core medical texts of this school. Although once thought to have been written by Hippocrates himself, today, many scholars believe that these texts were written by a series of authors over several decades. Since it is impossible to determine which may have been written by Hippocrates himself, it is difficult to know which Hippocratic doctrines originated with him. The existence of the Hippocratic Oath implies that this "Hippocratic" medicine was practiced by a group of professional physicians bound (at least among themselves) by a strict ethical code. Aspiring students normally paid a fee for training (a provision is made for exceptions) and entered into a virtual family relationship with his teacher. This training included some oral instruction and probably hands-on experience as the teacher's assistant, since the Oath assumes that the student will be interacting with patients. The Oath also places limits on what the physician may or may not do ("To please no one will I prescribe a deadly drug") and intriguingly hints at the existence of another class of professional specialists, perhaps akin to surgeons ("I will leave this operation to be performed by practitioners, specialists in this art").