Institutio Oratoria

But the appeal which will carry most weight is the appeal to pity, which not merely forces the judge to change his views, but even to betray his emotion by tears. Such appeals to pity will be based either on the previous or present sufferings of the accused, or on those which await him if condemned. And the force of our appeal will be doubled if we contrast the fortune which he now enjoys with that to which he will be reduced, if he fail.