Of the contract of agency there are five modes. A man gives you a commission either for his own exclusive benefit, or for his own and yours together, or for that of some third person, or for his own and the third person's, or for the third person's and yours. A commission given simply for the sake of the agent gives rise in reality to no relation of agency, and accordingly no obligation comes into existence, and therefore no action.

1 A commission is given solely for the benefit of the principal when, for instance, the latter instructs you to manage his business, to buy him a piece of land, or to enter into a stipulation as surety for him.

2 It is given for your benefit and for that of your principal together when he, for instance, commissions you to lend money at interest to a person who borrows it for your principal's benefit; or where, on your wishing to sue him as surety for some one else, he commissions you to sue his principal, himself undertaking all risk: or where, at his risk, you stipulate for payment from a person whom he substitutes for himself as your debtor.

3 It is given for the benefit of a third person when, for instance, some one commissions you to look after Titius's affairs as general agent, or to buy Titius a piece of land, or to go surety for him.

4 It is for the benefit of the principal and a third person when, for instance, some one instructs you to look after affairs common to himself and Titius, or to buy an estate for himself and Titius, or to go surety for them jointly.

5 It is for the benefit of yourself and a third person when, for instance, some one instructs you to lend money at interest to Titius; if it were to lend money free of interest, it would be for the benefit of the third person only.

6 It is for your benefit alone if, for instance, some one commissions you to invest your money in the purchase of land rather than to lend it at interest, or vice versa. But such a commission is not really so much a commission in the eye of the law as a mere piece of advice, and consequently will not give rise to an obligation, for the law holds no one responsible as on agency for mere advice given, even if it turns out ill for the person advised, for every one can find out for himself whether what he is advised to do is likely to turn out well or ill. Consequently, if you have money lying idle in your cashbox, and on so and so's advice buy something with it, or put it out at interest, you cannot sue that person by the action on agency although your purchase or loan turns out a bad speculation; and it has even been questioned, on this principle, whether a man is suable on agency who commissions you to lend money to Titius; but the prevalent opinion is that of Sabinus, that so specific a recommendation is sufficient to support an action, because (without it) you would never have lent your money to Titius at all.

7 So too instructions to commit an unlawful or immoral act do not create a legal obligation—as if Titius were to instigate you to steal, or to do an injury to the property or person of some one else; and even if you act on his instructions, and have to pay a penalty in consequence, you cannot recover its amount from Titius.

8 An agent ought not to exceed the terms of his commission. Thus, if some one commissions you to purchase an estate for him, but not to exceed the price of a hundred aurei, or to go surety for Titius up to that amount, you ought not in either transaction to exceed the sum specified: for otherwise you will not be able to sue him on the agency. Sabinus and Cassius even thought that in such a case you could not successfully sue him even for a hundred aurei, though the leaders of the opposite school differed from them, and the latter opinion is undoubtedly less harsh. If you buy the estate for less, you will have a right of action against him, for a direction to buy an estate for a hundred aurei is regarded as an implied direction to buy, if possible, for a smaller sum.

9 The authority given to an agent duly constituted can be annulled by revocation before he commences to act upon it.

10 Similarly, the death of either the principal or the agent before the latter commences to act extinguishes the agent's authority; but equity has so far modified this rule that if, after the death of a principal and without having notice of his decease, an agent executes his commission, he can sue on the agency: for otherwise the law would be penalizing a reasonable and unavoidable ignorance. Similar to this is the rule, that debtors who pay a manumitted steward, say, of Titius, without notice of his manumission, are discharged from liability, though by the strict letter of the law they are not discharged, because they have not paid the person whom they were bound to pay.

11 It is open to every one to decline a commission of agency, but acceptance must be followed by execution, or by a prompt resignation, in order to enable the principal to carry out his purpose either personally or by the appointment of another agent. Unless the resignation is made in such time that the principal can attain his object without suffering any prejudice, an action will lie at his suit, in default of proof by the agent that he could not resign before, or that his resignation, though inconvenient, was justifiable.

12 A commission of agency may be made to take effect from a specified future day, or may be subject to a condition.

13 Finally, it should be observed that unless the agent's services are gratuitous, the relation between him and the principal will not be agency proper, but some other kind of contract; for if a remuneration is fixed, the contract is one of hiring. And generally we may say that in all cases where, supposing a man's services are gratuitous, there would be a contract of agency or deposit, there is held to be a contract of hiring if remuneration is agreed upon; consequently, if you give clothes to a fuller to clean or to finish, or to a tailor to mend, without agreeing upon or promising any remuneration, you can be sued by the action on agency.