Arthur Dimmesdale stands by wordlessly and watches Hester bear the shame and humiliation of pubic punishment for the sin for which he was as responsible as she. His guilt for having violated the laws of his church is deepened by his guilt for remaining silent. From that moment, his physical and spiritual deterioration begins.
In Chapter 8, Dimmesdale interacts with Hester for the first time since she had stood on the scaffold. When it appears Hester might lose possession of Pearl, she communicates in an unspoken way that Dimmesdale must help her. He does. He dares to speak up, making a strong case for Hester keeping her child, explaining his reasoning in regard to the spiritual benefits that would result from Hester and Pearl's staying together. The strength of Dimmesdale's vehement appeal is not lost on Roger Chillingworth as he observes the scene.
Finally, Dimmesdale's previous isolation from Hester and Pearl is broken again when the child--his child--takes his hands into her own and lays her cheek against them. Dimmesdale's response is significant:
The minister,—for, save the long-sought regards of woman, nothing is sweeter than these marks of childish preference, accorded spontaneously by a spiritual instinct, and therefore seeming to imply in us something truly worthy to be loved,—the minister looked round, laid his hand on the child's head, hesitated an instant, and then kissed her brow.
There is a tenderness in him toward Pearl that has not been demonstrated previously. These feelings surely would have made his guilt and isolation even more difficult to bear.