Does anyone say that dying for a cause is always irrational? I wouldn't gloss Heidegger's freedom-toward-death, like that, but it might be broadly similar.
On the one hand, I would prefer to die unresolved, like Camus suggests, and due to if anything the sheer frustration of life and death. And I think, martyrdom aside, this may have parallels in promises of eternal life, found in religion.
But is there something horridly weak and cowardly, in having no cause, love, which is worth dying for?
Dying for a reason - suicide
I am inclined to say that rational action just is action done for a reason or (I'll concede at a stretch) for an 'all things considered' reason or set of reasons. Not in the least inclined to suicide myself, I can easily imagine that someone might consider they have a reason, even an all things considered reason, to end their own lives. If they act on this, they act rationally. Only if you build in an assumption that it is necessarily irrational to (want to) end one's life, is their action irrational.
But where does that assumption come from ? What reason do we have to accept it ? Without it, there is no case for saying that killing oneself for a reason is ever irrational, let alone always so. If there is a divine command not to commit suicide, then either that command is evident to reason, in which case one does not have an 'all things considered' set of reasons for committing suicide since this reason is not considered, or it is not evident to reason, in which case it has no place in one's reasons for action. If one accepts the divine command on grounds of faith, not reason, then one has a reason to act on one's faith and eschew suicide. But in this case again, one does not have an 'all things considered' set of reasons for committing suicide since this different reason - of faith - is not considered. Whether faith itself is rational is another issue : still I would say that even if faith is irrational, if one believes in it one is rational in acting on it.
But all this only shows at most they are can be conditions on which it would not be rational to commit suicide, not that it is always irrational simpliciter to do so.
Dying for a reason - dying for a cause
Rosa Luxemburg : 'Being human means joyfully throwing your whole life "on the scales of destiny" when need be but all the while rejoicing in each sunny day and every beautiful cloud' (Quoted in Raya Dunayevskaya, Luxemburg, Women's Liberation and Marx's Philosophy of Revolution', init.)
I rather think that the rationality of suicide is not your principal concern. You are thinking, I take it, of dying for a cause - a religion, a personal or political faith, or a moral imperative to save another person. This kind of thing. But the same arguments advanced for the rationality of suicide carry straight across. If the promotion of a religion, a personal or political faith, or the moral imperative of a situation, gives you a reason or an 'all things considered' reason or set of reasons to relinquish your own life then no irrationality is involved in sacrificing yourself. How should it be ?
Ah but, comes the reply. You have forgotten a vital connexion :
Rationality and self-interest
If we make a privileged connexion between rationality and self-interest, the cases above are put in doubt. Or some of them. It hardly serves my self-interest to lose my life in a blaze in order to save a child. But there is no such privileged connexion. The connexion is between rationality and one's 'interests' (not self-interest unless this happens to be among one's interests), that is, the things and matters and people that concern one. They and the risks and opportunities to which they are open can certainly provide reasons for action, even for action at the cost of one's life.
Doesn't the quotation from Rosa Luxemburg express your entire position ?
Anyone who asigns our reason and ethics as determined by evolution, would have to see actions that prevent reproduction or further reproduction, as counter to our fundamental natures. War & conflict that only risk these things, and choices made that benefit kin and so related genes would be limits on this.
This view places reason itself as merely in service of the propagation of our genes, and even if that holds them to that as a fundamental evaluation, we would still be free to reason our way to other choices like antinatalism, even though they cannot be expected to suceed in the the selection process. The selectin process determines which ideas endure and involves how they benefit their holders and their co munities. We implicitly accept the idea that ideas which suceed in propagating are at least more meaningful or deserving of accounting for, if not as necessarily being more correct.
Foucault described ideas as fundamnetally about power relations, as needing to be evaluated for their role in this. This view is not necessarily nihilistic or undermining of morality though, our mental infrastructure can provide real benefits like science does and win wars, and ethically membership of the international co munity that advocates for instance human rights can provide substantial benefits socially and in trade that makes them more successful than other systems.
Are you asking if there is a particular philosopher who held the belief that dying for a cause was always irrational, or merely someone who articulated this argument?
One way to start is to understand dying "for a cause" as someone choosing to be in a situation where there is an increased chance of death, as an instrument to achieving some other aim which benefits others.
You could argue (convincingly, I think) that we do this almost every day in some capacity by getting out of bed to work to sustain our lives which benefits the people around us. Barring the discovery of immortality, we will all die eventually, so our lives are themselves "dying for a cause" so long as we are not entirely selfish at all times.
"dying for a cause" seems difficult to make precise, but one definition is that in order to die "for a cause" the people who know of your death must think of you as a martyr.
One way someone could conclude that dying "for a cause" is always irrational is if they believe both in (1) the self-interest theory of morality*, i.e. that as individuals we have most reason to do what would make our lives go best, and (2) that dying can be either bad or good for us.
If you believe (1) and (2) then the only rational reason to choose to increase one's likelihood of death is if you believe that by not dying your life would go worse (e.g. if you expect to be tortured and then killed in the near future).
*As articulated by Derek Parfit in Reasons and Persons.
