[1] The ability to discern a distinction between financial accounts in general and a literal contract plagues early sources.
Gaius, writing later, considers the disbursement the central element, and so this throws doubt on the efficacy of the earlier sources to establish the presence of a literal contract.
[3] Dragomir Stojčević notes the presence of the terms "af" and "abs" in the early texts of Velius Longus, drawing on the later works of Cicero to demonstrate that they were only used in conjunction with literal accounts.
[4] However, the distinction between general accounts and a literal contract cannot be shown to any certainty, and the texts are still concerned only with the recording of receipts.
[4] Cicero's account of a knight called C. Canius, known to have been active in 115 BC, does at least provide significant (and accepted) evidence of them literal contract's existence at this time.
[4] Alan Watson identifies the main areas of uncertainty, which, if showed one way or the other, would elucidate the dating problem.
It might have done if the literal contract was used to consolidate several different debts between two parties, to simplify them into a single action, but none of the texts point to this: they refer to a singular preceding obligation.
[6] The consent of the debtor was probably required: this is stated as fact by some modern lawyers,[7] although Watson points to the alternative explanation of Stojčević.
Under the normal explanation, the tablets of Herculaneum show that something other than the written contract itself was required, necessarily debtor's consent.
[7] Gaius' account indicates that it was a previous obligation was required in the classical law, and Watson believes this can be conclusively shown for the last century of the Republic.
He identifies them with the peregrine's law only; after the extension of citizenship to the majority of the free peoples of the Empire by Caracalla, they continued to be used, but only in an evidentiary role.