John Locke's A Letter Concerning Toleration introduces an early form of John Rawls's “original position” in order to shift the rhetorical ground in seventeenth-century England in favor of religious toleration. His method, which I call “Lockean switching,” seeks to induce readers to switch perspectives on the question of coercion of religious belief. This method yields three insights. First, although liberals typically assume that group identification stimulates passions beyond our ability to reason, Lockean switching reveals that the emotive qualities of group interest can actually help reinforce our commitment to and understanding of liberal principles. Locke thus insists that imagination and emotional response can encourage reason and increase impartiality. Locke's carefully crafted scenarios force readers to consider hard political questions, something underscored by comparing Locke's rhetorical strategies with those of two other important liberals, Montesquieu and Rawls. Second, Locke's invocation of remote “outsiders” such as Jews and pagans humanizes the hated minorities of his time and place. But it also risks reifying the majority group and inflaming prejudice. Finally, Lockean switching reminds us that liberals must be alert to the dangers of pushing readers to accept principles that are reasonable but impossible to implement. By exploring Locke's method of shifting perspectives, and connecting it to a broader liberal tradition of “switching,” I argue that contemporary liberals can use imagination and group identification to help reinforce the commitment of individuals and groups to liberal principles with which they might not otherwise identify. I conclude by illustrating this with regard to controversies surrounding the toleration of gays, lesbians and transgendered individuals in the US.