Ivan, let me address the Battlefield scenario first- as I remember that part clearly. He gave his life so that the others of his squad might have a better chance of survival...that he knew he would die in the act does not, by itself, constitute suicide in my opinion. You could argue that what he did was 'altruistic suicide' - that is, he died so that others may live but that form is generally not considered 'suicide' as his death had meaning, the purpose being to save the lives of others. HIS was a courageous and honorable act- would you disagree? The unnamed Viking who held Stamford Bridge long enough for his compatriots to get organized did so to buy his people time...again, not suicidal. Oh, he might've been suicidal, but his actions do not constitute a suicide, especially since he was slain by the hand of another.
With regard to Masada, I thought it was just the one man who was tasked with killing everyone else, then himself? So one suicide, and hundreds of murders- to avoid Roman enslavement; I suppose you could call that heroic in that they robbed the Romans of their victory...or did they? Rome wanted to protect those palaces- the Jewish raiders who'd taken over were all dead so in the end, Rome got what it wanted. At least as far as I look at it.
I have read where the Romans felt that to 'fall upon one's sword' was an honorable act, rather than facing 'the music' as it were. Culture based, like the Japanese...but I don't consider it heroic or honorable to take one's own life for any reason, especially when that reason is to avoid something else thought to be worse than death. Barring the instance where it is given so that others may be spared, which I do not consider suicide, but self-sacrifice. There is a difference.
Thich Quang Duc...can't call him a coward, he didn't just knife himself or put a bullet to his head, he burned himself. He killed himself to protest the persecution of his fellow Buddhists...I suppose you could classify that as being an instance where his life was given so that others may be spared? It was courageous, even if the persecutions did not end w/his self-sacrifice...it wasn't until Diem was assassinated that things began to get better, but he did make it so that said atrocities were brought to light in the world eye.
Duncan's friend's act falls within the confines of his culture- his whole life revolved around Bushido, and I suppose to a lesser degree, shibui. You also wrote: "BTW a Samurai could also commit suicide in protest of a command he did not want to carry out. Some dishonorable Daimyo would order Samurai they wished to dispose of to do something they knew the man in question would rather die than carry out."
I get the impression that the samurai in question knows in advance that it is simply a command designed to cause him to perform seppuku rather than carry out the order- if that is so, then his is a steadfast, if foolhardy adherence to custom. It is one thing to know that you will die...we all must at some point, but to speed yourself along because someone else is making you do something you know to be wrong- and only does so because they know your honor would only allow one course- I cannot call that courageous, or honorable.
Keeping in mind that I have my own belief system for which this does not compute, but it is mine own opinion and I still stand by it.
