or replies in a way which does not correspond with the question, as where one  stipulates to be given ten and the other promises five, or one stipulates unconditionally  and the other promises conditionally.3637<It will also be ineffective if one  stipulates as follows: Do you promise to pay if a ship arrives from Asia today?,  for this is preposterously framed. Nevertheless, though it is preposterous, it is not  to be rejected.>3839Nor will a stipulation be valid if an impossible condition is  added, the fulfillment of which nature makes impossible, as Do you promise to  pay if I touch the sky with my finger? But if it is put in this way, If I do not  touch the sky with my finger, the stipulation will then be valid, because it is  unconditional and can be sued upon at once.40
The judicial stipulation.
 41A stipulation may be judicial or conventional: judicial, made by order of the  judge or praetor; conventional, arising from the agreement of the parties, not by  direction of the judge or praetor, of which there are as many kinds almost as there  are things about which men may conclude agreements.42 With all these matters  the king's court does not meddle,43 save occasionally as a matter of grace.
If several things are made the object of a stipulation.
 44If several things are included in a stipulation and the promisor simply answers  I promise to give, he is liable for them all. If he promises to give only one, or some,  an obligation is contracted for those comprised in his answer, for of the several  stipulations one or some are taken to be completed; when there are several matters  a reply ought to be made to each.45
Who cannot stipulate.
 46Finally we must consider those who can neither stipulate nor promise, that we  may know those who may enter into a stipulation. 47It is clear that one who is  dumb can neither stipulate nor promise, since he cannot speak or utter the words  appropriate to a stipulation. The same is true of a deaf mute, for it is essential that  the stipulator hear the words of the promisor and the promisor those of the  stipulator,48 unless one says that they may enter into a stipulation by a nod or a  writing.4950What we have said applies not to one who is hard of hearing but to  him who is stone-deaf.51 That a stipulation and obligation may be created by a  writing is obvious, because 52if it is written in an instrument that a person has  promised, it is treated exactly as if an answer had been made to some preceding  question.5354A lunatic cannot stipulate or conduct any transaction because he does  not understand what he is doing. Nor can an infant or one just out of infancy (who  does not greatly differ from a lunatic)55 unless what is done is to his advantage and  done with the authority of his tutor.56