We say: He can learn through study and practical training before he himself undertakes treatment. But for an educated person who is not yet proficient to come and conduct experiments on healthy people until they die—this is not permissible.

There is a third condition for their not being liable which the author did not mention: their work must be done with the permission of a legally accountable person—that is, an adult of sound mind—or of the guardian of one who is not legally accountable. Thus, if a boy goes to a circumciser and says, “Circumcise me,” and the circumciser performs a normal circumcision, but the boy dies because the wound becomes infected, then he is liable.

His statement, “Nor is a shepherd who does not transgress [liable]”: a shepherd is one who tends livestock, whether camels, sheep, gazelles, or other animals.

A shepherd may be a private employee or a joint employee. If his work is defined by a period of time—for example, if he works for you for a month tending your sheep—then he is a private employee. But if he tends his own flock and takes charge of your sheep and those of others, then he is a joint employee.

A shepherd is not liable if he neither transgresses nor is negligent, because he is a trusted custodian: the animals came into his possession with their owner’s permission, so his possession is one of trust. If wolves attack this shepherd and devour whatever livestock they devour, is he liable?

He is not liable, but he must defend them.

A second example: a shepherd is negligent. He stops the livestock in the middle of a valley while the sky is overcast and rain is likely to fall. Then Allah sends down rain, the valley floods, and sweeps away the livestock. He is liable, because he was negligent.

A third example of one who transgresses: a shepherd had between himself and the land he wished to reach