In 2005, John Harris published a paper in the Journal of Medical Ethics in which he claimed that there was a duty to support scientific research. With Sarah Chan, he defended his claims against criticisms in this journal in 2008. In this paper I examine the defence, and claim that it is not powerful. Although he has established a slightly stronger position, it is not clear that the defence is sufficiently strong to show that there is a duty to support scientific research. Important questions about fairness, about rescue, and about the relationship between reasons and obligations to act can still be raised; and these questions are important enough to destabilize the defence.