Sadness

What is sadness? It arises from the natural mind. In this case, I would say the natural mind includes the heart, because I also suspect that computation happens in the heart. So sadness.... I think it arises from the process of deconstructing computational structures. The brain develops an infrastructure to support computation about something/someone that we need or want to pay attention to. When that person dies or we lose the thing, the computational infrastructure becomes useless and has to be deconstructed. I think that process gives rise to what we call sadness.