in carpentry, and someone came to one of them and said, “Make me a door.” He replied, “No problem; I will make the door.” In this case, if the one who made the agreement does not make the door, the other is obliged to make it, because they are partners jointly liable for one another. Whatever either of them undertakes is binding upon the other.

This also applies when their trades differ—for example, if one is a woodworker and the other a blacksmith. If the woodworker undertakes to make a wooden door, is the blacksmith obliged to do so?

The answer is yes: according to the author’s statement, he is obliged, because they are partners. The blacksmith may be told, “Make the wooden door for us.” If he says, “I am not a woodworker; I do not know how,” we say to him, “Hire someone to make it for us, because you are bound by what your partner has undertaken, and it is therefore binding upon you.” The reverse is likewise true. If someone comes to the blacksmith and says, “Make me a wooden door,” and he undertakes it, then it is binding upon his partner. In any case, whatever work either of them undertakes is binding upon the other, because they are partners and each is bound by what the other undertakes. This is the established position of the school.

A partnership of labor has several forms, including the author’s statement: “It is valid for gathering grass and gathering firewood.” Gathering grass is for two men to go out into the open country to collect grass and sell it in the market. One of them says to the other, “We are partners in whatever we earn.” The other replies, “No problem; let us form a partnership, and each of us may go to a valley.” Each of them then returns with a load of grass.

Gathering firewood is similar: they go out into the open country to collect firewood to sell, and he says: