Suppose someone is thinking about killing himself. Can philosophers or philosophy give him reasons for or against doing it? Or isn't suicide a philosophical subject?

I think that the primary thing that is wrong with murder is that it ends a life that is valuable, both for the person living it and for people who love her or otherwise benefit from her existence. In contrast, I think that often, when people consider suicide, they believe that their life is no longer worth living. They are in a great deal of physical or psychological pain, and they don’t foresee that things are going to get much better. They don’t believe that their existence is particularly important to others, and they can’t imagine that their value to others will change soon. They don’t believe that their life has much point, and they can’t figure out what could possibly give their lives meaning. For them, non-existence seems to be an improvement over existence, not because they assign a positive value to non-existence, but because existence seems to have such a negative value. If they are right, then suicide is not wrong in the way that most murders are wrong. However, I think many people who...