PAROL CONTRACTS PRIOR TO ASSUMPSIT. 259 constituted the quid pro quo for the seller's duty to suffer the buyer to take possession of the chattel sold. If the bargain was for the reciprocal exchange of chattels, the delivery of the chattel by the one party would be as effective a quid pro quo as payment of purchase-money to support an action of Detinue against the other party. It was hardly an extension of principle to treat the delivery of the buyer's sealed obligation for the amount of the purchase-money as equivalent to actual payment of money, or delivery of a chattel, and accordingly we find in Y. B. 21 Edward III. 12-2, the following statement by Thorpe (Chief Justice of the Common Bench in 30 Edward III.) : " If I make you an ob- ligation for £o for certain merchandise bought of you, and you will not deliver the merchandise, I cannot justify the detainer of the money ; but you shall recover by a writ of Debt against me, and I shall be put to my action against you for the thing bought by a writ of Detinue of chattels." But it was a radical departure from established traditions to permit a buyer to sue in Detinue when there was merely a parol bargain of sale without the delivery of a physical res of any sort to the seller. But this striking change had been accomplished by the time of Henry VI. The new doc- trine may be even older, but there seems to be no earlier expres- sion of it in the books than the following statement by Fortescue, C. J. : " If I buy a horse of you, the property is straightway in me, and for this you shall have a writ of Debt for the money, and I shall have Detinue for the horse on this bargain." ^ From the mu- tuality of the obligations growing out of the parol bargain without more, one might be tempted to believe that the English law had developed the consensual contract more than a century before the earliest reported case of Assumpsit upon mutual promises.^ But this would be a misconception. The right of the buyer to maintain Detinue, and the corresponding right of the seller to sue in Debt were not conceived of by the medieval lawyers as arising from mutual promises, but as resulting from reciprocal grants, — each party's grant of a right forming the quid pro quo for the cor- responding duty of the other.^ 1 Y.B. 20 Hen. VI. 35-4; Y. B. 21 Hen. VI. 55-12. See, to the same effect, Y. B. 37 Hen. VI. 8-18, per Prisot, C. J. ; Y. B. 49 Hen. VI. 18-23, per Choke, J., and Brian; Y. B. 17 Ed. IV. 1-23. See also Blackburn, Contract of Sale, 190-196. 2 Peck 57. Redman (1555), Dy. 113, appears to be the earliest case of mutual promises. 8 If the bargain was for the sale of land and there was no livery of seisin, the buyer had no common-law remedy for the recovery of the land, like that of Detinue for chat- tels. Equity, however, near the beginning of the sixteenth century, supplied the coiu- 35