Tacitly consenting to donate one's organs.

The common objection to opt-out systems of postmortal organ procurement is that they allow removal of a deceased person's organs without their actual consent. However, under certain conditions it is possible for 'silence'--failure to register any objection--conventionally and/or legally to count as genuine consent. Prominent conditions are that the consenter should be fully informed about the meaning of his or her silence and that the costs of registering dissent should be insignificant. This paper explicates this thesis and discusses some possible objections to it: (1) it cannot possibly be guaranteed that each citizen is aware of the meaning of silence; and (2) the system is slightly manipulative because it exploits a common defect in autonomous decision-making.