Man has an unalienable right to life, which means the right cannot be removed from the person by any means, including consent. You do not have a right to allow yourself to be enslaved, so it would seem to logically follow that you don’t have a right to kill yourself.
However, in all common cases of consenting to rights violations against yourself, you are allowing another person to commit a violative act against you. With suicide, that is not the case.
So can one violate their own rights? My own understanding of morality is not currently sufficient to answer this question, and it seems to be on the leading edge of mankind’s understanding, if not just out of reach (at least at this time).
I suspect suicide may be immoral (i.e. a cause that generates undesirable consequences). Maybe it’s just as simple as how it effects families, or what it includes in the experience of mankind on the whole.
Immorality is error, and certainly there is error at play with suicide (most notably, inaccurate valuation of the self, and thereby the worth of every individual, since we all have equal inherent worth). Lots to consider here...
I cannot see how killing oneself could possibly be a violation of their own inalienable right to life. That would be like saying that someone who takes a vow of silence is violating his own right to speech. Part of any right is the freedom not to exercise it if you choose. To say that someone MUST live even if they don't want to is tyranny.
I know, it's a weird situation. I'm just exploring this, not asserting anything. We're not getting anyone else involved in this suicide scenario because that changes the game, so that tyranny would have to be self-tyranny: "To be moral I cannot violate my own right to life, thus I must FORCE myself to live." But how can one be said to tyrannize themselves?
It seems to be as you say, that part of any right is the freedom to not exercise it: I have the right to build a canoe, but I choose not to exercise that right - that's fair enough. But what about I have the right to not be enslaved, but I choose not to exercise it? This is not a freedom. By allowing yourself to be enslaved, you allow the immoral action of slavery to take place, and therefore the cause-and-effect of moral law applies and the universe is harmed in some small way.
But is the key distinction whether or not anyone else is involved? Is it immoral to cut myself on purpose? To degrade myself, torture myself? Suicide would seem to follow whatever answer we come up with, and I suspect it may be immoral to do so. Ancient traditions seem to have come to the same conclusion, calling suicide "sin".
And is it not sin? Is it not error, embracing falsity, denying the reality of your own self-worth? Does this not have some effect on other living beings; maybe energetically, by bringing non-love into the co-creation of our world?
I don't know, but I think it's not so cut-and-dry as saying "it's moral to do anything, as long as it's only to yourself" because we cannot truly isolate ourselves - what happens to one, happens to all in some sense. This is one of the aspects of morality that makes it so important to care about what's happening outside of our own small pocket of the world - none of us are truly free until ALL are free.