Why does Edgar consent to allow Cathy to make a visit to Linton in Chapter 25? Is this a wise choice?

Cathy's father consents in part because he is near death, and a marriage with Linton would secure Cathy's future. However, he and the others are unaware that Heathcliff, with his revenge near and his son in ever-poorer health, is to become even more cruel in his plans.