William Simkulet has challenged our recent argument that parents have an obligation to donate organs and tissues to the same extent that abortion is restricted. The central feature of our argument is that parents have a duty to protect their offspring. If this duty is sufficient to require gestation of a fetus, then it is also sufficient to require that the parent allow offspring the continued use of their organs and tissues. Simkulet challenges this argument on several fronts. In this (...) paper, we refute each of these challenges and further clarify the contours of our argument. In particular, our rebuttal highlights the relation between special obligations an agent-neutral obligations and the biological foundation of the duty to protect. (shrink)