I am very disappointed with James’ behavior this week. He is blinded by love and seems to have changed allegiances from his family to Isabella.

Once Isabella starts crying, he joins in the Thorpe’s haranguing of Catherine to put off the Tilney’s in favor of their drive to Clifton. Catherine is greatly troubled by this. “This was the first time of her brother's openly siding against her.” Catherine is acting on the principles their parents taught them, and instead of acknowledging her convictions and the pain she is also feeling, he can think only of Isabella. Not only does he side against Catherine, he becomes “quite angry” and scolds her:

"I did not think you had been so obstinate, Catherine," said James; "you were not used to be so hard to persuade; you once were the kindest, best-tempered of my sisters."

That “you were once” must have cut poor, sweet Catherine to the quick.

”It was painful to her to disappoint and displease them, particularly to displease her brother; but she could not repent her resistance.”