“I can remember when I was young I believed death to be a phenomenon of the body; now I know it to be merely a function of the mind — and that of the mind of the ones who suffer the bereavement.” (44)
Faulkner, William. As I Lay Dying: The Corrected Text. First Vintage International Edition. New York: Vintage Books, 1990. Print.
It seems to me that Peabody is saying that death is an experience of the people left behind, more so than the people who have actually died. If I’m interpreting this correctly, this would make sense as this communal experience appears to be a running theme of the novel.