A mortgage is a dead pledge, mort gage in old French, and the lawyers never agreed on what died. Edward Coke, writing in 1628, said it died either way: if the borrower didn’t pay, the land was dead to him for good, and if he did, the pledge was dead to the lender. The twelfth-century treatise known as Glanvill had another answer. In a living pledge the lender held the land and its harvests paid the debt down, so it worked its own way home. In a dead pledge the lender kept the harvests and the debt never moved. So the word is either a promise that can only end by dying, or a field that works all year and none of it counts. Paying one off has a word from the same root, amortise: to deaden it, a little each month.