An argument is derived from the kind of word, thus: "Since all the money has been bequeathed to the woman, it is impossible that that ready money which was left in the house should not have been bequeathed. For the species is never separated from the genus as long as it retains its name: but ready money retains the name of money: therefore it is plain that it was bequeathed."
An argument is derived from the species, which we may sometimes name, in order that it may be more clearly understood; in this manner: "If the money was bequeathed to Fabia by her husband, on the supposition that she was the mother of his family; if she was not his wife, then nothing is due to her." For the wife is the genus: there are two kinds of wife; one being those mothers of a family which become wives by coemptio; the other kind are those which are only considered wives: and as Fabia was one of those last, it appears that nothing was bequeathed to her.
An argument is derived from similarity, in this way: "If those houses have fallen down, or got into disrepair, a life-interest in which is bequeathed to some one, the heir is not bound to restore or to repair them, any more than he is bound to replace a slave, if a slave, a life-interest in whom has been bequeathed to some one, has died."
An argument is derived from difference, thus: "It does not follow, if a man has bequeathed to his wife all the money which belonged to him, that therefore he bequeathed all which was down in his books as due to him; for there is a great difference whether the money is laid up in his strong box, or set down as due in his accounts."
An argument is derived from contraries, thus: "That woman to whom her husband has left a life-interest in all his property, has no right, if his cellars of wine and oil are left full, to think that they belong to her; for the use of them is what has been bequeathed to her, and not the misuse: and they are contrary to one another."
IV. An argument is derived from adjuncts, thus: "If a woman has made a will who has never given up her liberty by marriage, it does not appear that possession ought to be given by the edict of the praetor to the legatee under that will; for it is added, that in that case possession would seem proper to be given by that same edict, according to the wills of slaves, or exiles, or infants."
Arguments are derived from antecedents, and consequents, and contradictories, in this way. From antecedents: "If a divorce has been caused by the fault of the husband, although the woman has demanded it, still she is not bound to leave any of her dowry for her children."
From consequents: "If a woman having married a man with whom she had no right of intermarriage, has demanded a divorce, since the children who have been born do not follow their father, the father has no right to keep back any portion of the woman's dowry."
From contradictories: "If the head of a family has left to his wife in reversion after his son the life-interest in the female slaves, and has made no mention of any other reversionary heir, if the son dies, the woman shall not lose her life-interest. For that which has once been given to any one by will, cannot be taken away from the legatee to whom it has been given without his consent; for it is a contradiction for any one to have a right to receive a thing, and yet to be forced to give it up against his will."
An argument is derived from efficient causes, in this way: "All men have a right to add to a common party wall, a wall extending its whole length, either solid or on arches; but if any one in demolishing the common wall should promise to pay for any damages which may arise from his action, he will not be bound to pay for any damage sustained or caused by such arches: for the damage has been done, not by the party which demolished the common wall, but in consequence of some fault in the work, which was built in such a manner as to be unable to support itself."