In the first Act of the play, the Earl of Northumberland awaits news of the fate of his son, Henry “Hotspur” Percy, who had lead an army against that of the King. After hearing various and varying reports, Hotspur’s death is confirmed. Northumberland uses a paradox to explain his surprising reaction to this bad news:
In poison there is physic, and these news,
Having been well, that would have made me sick,
Being sick, have in some measure made me well.
And as the wretch whose fever-weakened joints,
Like strengthless hinges, buckle under life,
Impatient of his fit, breaks like a fire
Out of his keeper’s arms, even so my limbs,
Weakened with grief, being now enraged with
grief,
Are thrice themselves.
First, he notes that even poisons share some chemical elements with “physic,” or medicine. Along similar lines, he suggests that, had he been healthy, news of his son’s death would have made him fall sick; however, because he was already a sick and elderly man, this news has instead “in some measure made [him] well.” He then explains his paradoxical argument that bad news has made him feel better: his “weakened” limbs have been “enraged with / grief” and are now “thrice” or three times as strong and powerful as they were before. Despite his physical limitations, then, Northumberland believes that his fury has re-animated his body and given him the strength to carry out his revenge against the King.