The marks of this ancestry are still visible in the contractual relationships of the fifth and fourth centuries BCE, and even later. Greek contract always generated this element of reciprocity of prestations1 except it was not the creator of legal effects, and in particular, it did not give birth to a legal action, a dike. Thus, deriving from exchange, every contractual relation had to be executed in a real way, ‘from hand to hand’, whatever the social or the economic status of the contracting parties. It is precisely this real, material character which gives the contract, whatever it may concern, its whole essence. In the loaning of money, for example, the responsibility of the debtor is founded on the fact that he has received a sum of money from the creditor, which he must return within the agreed period, and not because he has promised to return an amount equal to the sum paid to him. In the rental of real property, the tenant in fact received the use of the property in contracting a deposit, because the depository always actually received goods to keep, it was always a real act, the transfer of a good which created as a consequence the responsibility of the recipient.