"I'm not even talking about blame, I'm talking about being available." (4.32)
Calvin believes that a parent is at least partially responsible for his child's actions, and he blames himself for the death of one son and the suicide attempt of another. Beth, though, distances herself from these issues as much as possible. She wants her children to exist completely independently of her. It's almost like she didn't even give birth to them.
"Are we going to live like this? With it always hanging over our heads?" (4.51)
Maybe a little guilt is healthy. But any guilt at all ruins Beth's idea of perfection, so she pushes any hint of it away as forcefully as she can.
She was right. He lied to her at lunch. He does not believe himself to be innocent. It has to be his fault, because fault equals responsibility equals control equals eventual understanding. (4.87)
Calvin, the tax attorney, puts his guilt into specific mathematical terms. Hey, whatever works for him to understand it. At least he accepts it, unlike Beth, who doesn't even acknowledge her own feelings…if she has any.
"Calvin, you get what you deserve." (6.21)
This line encapsulates Beth pretty well—insensitive and hypocritical. If her logic is true, she should consider that she, too, is also getting what she deserves. But she doesn't have enough self-awareness to understand that.
"I am never going to be forgiven for that, never! You can't get it out, you know! All that blood on her rug and her goddamn towels—everything had to be pitched!" (14.10)
It's sad that this is what Conrad worries about. He attempted to take his own life, yet he believes his mother blames him for ruining her towels. Yet Beth never attempts to dissuade Conrad from this belief, so maybe he's right, and the towels were what she cared about most.
"I think I just figured something out. […] Who it is who can't forgive who." (14.32, 14.34)
As much as Conrad blames his mother, Dr. Berger believes that there comes a point when he must forgive her for being a stone-cold ice queen.
"Guilt. Yes. […] Well, I'm guilty. And lucky, too. I was there at the right time. I could have been at a meeting, we could have both been at meetings." (17.67)
This line recalls an earlier quote in which Calvin says he believes that "Being a father is more than trusting to luck" (2.15). Whenever he experiences bad luck, Calvin blames himself for it. He doesn't give himself credit for being there at the right time.
"For surviving, maybe. No, that's not it, for being too much like her. Hell, I don't know." (17.82)
To stop blaming himself, Conrad first has to figure out what it is that he blames himself for. Both of the points he makes here are valid. He has survivor's guilt for living when his brother died. And he definitely sees himself in his mother—but only in her less desirable qualities, like her selfishness and isolation.
Life is not a series of pathetic, meaningless actions. Some of them are so far from pathetic, so far from meaningless as to be beyond reason, maybe beyond forgiveness. (19.67)
Calvin stops blaming himself and starts blaming his wife as the book progresses. Because the book is told from his point of view, this is seen as progress. It isn't perfect, but for Calvin, it's a step in the right direction.
"Punishment doesn't do a damn thing for the guilt, does it? It doesn't make it go away. And it doesn't earn you any forgiveness." (27.76)
Conrad is the type of person to beat himself up (or cut himself with a razor blade) to punish himself. In his view, he doesn't get any punishment from his parents, so he feels guilty as a result.