Why does Cassy vow never to marry anyone but Tom, despite his protests?

Why does Cassy vow never to marry anyone but Tom, despite his protests? Do you agree with her "small epiphany" later in the novel that "it never had been the wilful act of a foolish young woman, but instead the centrepiece of her whole life's design"?

Frankly, I had trouble with Cassy's decision to remain single. She was young when Tom died. I wish she had made another choice; still, she was satisfied with her life at the end.

I felt that Cassandra's decision made sense in the cultural context: she had seen her promise not only as a promise to Tom but as a vow to God. Though her decision to refuse Mr. Hobday was obviously heartbreaking--I'm sure a lot of readers in that moment were rooting for Cassy to change her mind.

It was a decision that is hard to understand in this time. Cassie took her vow seriously and I do think that was consistent with that time period.

I think Cassy thought it was the honorable thing to do! Even though she may have had second thoughts, I think she felt that her promise would give him reason to try harder to stay safe and return.

While I respect Cassy's decision to remain faithful to her promise to Tom to never marry another, in keeping with the solemnity and higher moral plane of vows made in that time period, her sister, Jane, also from the same time and place, was unable to come to terms totally with Cassandra's refusal to accept Mr. Hobday and experience a life of happiness and security with him.

This vow made no sense to me. I think she wanted to give him more reason to return safely, as mentioned earlier, but it did become 'the centerpiece of her whole life's design'. I'm not sure if the vow was because of the particular era or not, considering that Jane disagreed with it.

I find it hard to understand. She had another chance after Tom's death for marriage and a family. Children were something she had said she wanted. But her choices did give her opportunities as a helper and caregiver to others, which she wouldn't have been able to do if she had a family of her own.

I don't think she wanted to marry at all--but if she was going to marry it would be best to marry into one of the families to which the Austens were already related. Once Tom was gone she would have to marry someone from away, so to speak--outside the circle of family and friends. That might require moving away from Jane or living with someone who didn't understand the Austens and their ways.

I felt this vow came in the heat of youth and passion. Tom was almost as much an Austen as he was a Fowle. Cassie was losing - for a time - a nearly constant companion, someone who was like a brother to her. She was young and in love and feeling the passion of both, and she made this statement before the alter of the village church with God as her guide.

Excellent question. I didn't get it. Seemed to me that given her circumstances she would have benefited from marrying after Tom died. I thought Tom something of a drip as the book went on. She was so sensible and pragmatic -- baffles me.

I never really fully understood this, but this is me seeing this from a 21st century standpoint. She and Tom had been viewed as the perfect couple and it had been expected they would eventually marry. It seemed to me she made this vow rather impulsively, perhaps as a way to convince herself that of course Tom would return from sea.

I did not understand her declaration to Tom. I really think she did not think she thought this would be something she might regret in the future. She was trying to keep Tom happy. I believe everyone has made statements like this and never think about what this would mean ahead, but once made, cannot be taken back.

I think she meant it at the time, as an affirmation to Tom of how much he meant to her and how important it was that he return safely. But she was so young. To live her whole life alone because of that vow? Well, she certainly took it as a commitment that she didn't want to break.
On the other hand, she had a lot of happiness in carrying for her nieces and nephews and in her close relationship with Jane.