Whereas, as we shall see later, medicine already possessed concepts that enabled it to define the unity of clinical teaching, the theoreticians failed to propose an institutional version of it: practical training was not simply the application of abstract knowledge (if so, it would be enough to entrust this practical teaching to the professors in the schools); nor could it be the key to this know ledge (which could be acquired only when this knowledge had been mastered), because, in fact, this practical teaching still concealed the technological structure of a medicine of the social group, whereas the university training was inseparable from a medicine that was so closely related to the theory of species.