  Second, the cooperation argument cannot be extended to justify extremely large sacrifices, such as the soldier falling on the grenade, that standard moral theories rank either as most important or supererogatory. The cooperation argument depends on a short-term loss (such as keeping a promise that it is inconvenient to keep) being recompensed by a long-term gain (such as being trusted in future promises). Where the immediate loss is one’s life (or irreplaceable features such as one’s sight), there is no long-term gain, and so no egoist argument for the sacrifice.