In this paper, I look at some arguments for introducing a greater degree of lay participation into decision-making in the criminal justice system and other central institutions. I distinguish two types of argument for the conclusion that we should introduce greater lay participation: the Correction Thesis, that lay participation is necessary to correct for certain limitations and biases inherent even in the best decision-making that is carried out by people in possession of superior knowledge of an issue; and the Common Ownership Thesis, that democratic self-governance generates responsibilities that we cannot simply devolve to a technical association or bureaucracy to sort out for us. I argue that the Correction Thesis is inadequate to provide a general justification for greater lay participation. Such a general justification might more plausibly be given by the Common Ownership thesis. But the latter must be improved before we can fully understand its scope and plausibility.