 So far then, a craft is defined by its goal and is a kind of knowledge. Fully developed, this knowledge is knowing how to accomplish a goal on the basis of an understanding of the goal; the understanding can be articulated in an account. The account informs and guides the skilled practice. A craftsman’s being able to articulate the goal is most fully developed, perhaps, in the Laws. The Athenian Stranger describes the distinction between the slave doctor and the doctor of free men as resting on the ability to give an account. The slave doctor relies on experience (empeiria) and has no account to give for his procedure. The free doctor not only has an account, he communicates it to his patients as a way of eliciting their cooperation in the course of treatment (720 b–d). Presumably, the patients come to appreciate the reasons for the actions the doctor undertakes as well as the regimen he prescribes because they better understand the nature of health and the way the treatments produce health. In fact, the empiric doctor laughs at the free doctor for instructing his patients — as though he were trying to make them into doctors themselves (857 d-e).