To which the person summoned may answer that, although the gift had an invalid  beginning, the said B. subsequently ratified and confirmed it before honest men,  and thus if, having changed his mind, he afterwards [seeks to impugn] his deed,  which he made1 his by his ratification and confirmation, that ought not to harm  him, since it ought to suffice that he once wished it.2
That the thing given be certain.
 3It is also necessary that a thing certain be comprised in a gift, for if the thing  is uncertain there is no gift. [The thing must be certain though when the gift is to  take effect may be uncertain, as where one says, I will give you such a thing when  it falls to me after the death of such a one, my ancestor, or when something is  done or not done, or when it occurs or does not occur.]4 And as the thing  given or promised must be certain, so the thing given in exchange or promised in  return must be certain, as homage and a certain service,5[and thus a gift falls into  one of the four innominate contracts,] as where I say I give you that certain  thing for your homage and service, the services must be certain and expressed in a  writing [or without a writing,] and having been so expressed all other services  and customs are remitted.6 If a charter is not made, recourse must be had to  common usage, that such and so much service be done as [is due from] that much  land in the same vill [or] of the same fee.7 If a dispute arises as to usage, recourse  must be had to an inquest of the country or to the grand assise. 8If a charter is  made the gift will be more secure,9 for a gift may be proved more easily and more  effectively by a writing and instruments than by witnesses or suit. But of charters  and the credibility of instruments more will be said below.10 It is also necessary  that certain words be used, as suitable to a gift as to a 11stipulation, as where I say,  Will you give me a hundred? and you reply, I will give, for a question is of no  effect unless followed by an answer appropriate to it, that is, I will give. From  such a question and answer an obligation at once arises.12 A gift is of no effect unless  there is mutual consent and agreement on the part of both the donor and the  donee, that is, that the donor have the animus donandi and the donee the animus  recipiendi,13[A bare statement in an account and a nude pact do not make  anyone a debtor.]14 [for] if I say I give you such a thing and have no intention  of giving it (and do not begin it by livery) the gift fails, as where I say, I give  you that thing and do not wish15 to hand it over, or suffer you to take it with you,  or if it is a tree that is given, to cut it down, the gift is without effect, because the  donor did not fully consent. 16There must also be no mistake in the thing given,  for if the donor