According to Jeremy Waldron, John Locke’s argument for the instrumental irrationality of persecution is fatally flawed. In this paper, Conti offers evidence that Waldron has misread Locke, and that Locke’s views about why persecution generally proves inefficacious have greater plausibility than Waldron allowed. According to Conti, Locke’s argument for the irrationality of intolerance does not, as has been thought, rest on a tendentious ontological distinction between ‘the will’ and ‘the understanding’, but on an account of the adverse psychological reaction of victims of persecution to their plight. Persecution, Locke argued, provokes in its victims feelings of distrust and hostility that diminishes the chances that they will convert to the religion that has persecuted them. An appeal to the ‘victim’s perspective’ in order to dissuade would-be persecutors was a fundamental part of his case for toleration, and one that was noticed and employed by other proponents of toleration.