Abstract: David Hartley ends the first part of his Observations on Man with an argument for necessitarianism that emphasises the obvious influence of motives upon choice, and that straightforwardly, and unusually, denies that we experience ourselves as free in our choices. Hartley’s style of philosophizing is taken up by Abraham Tucker and Joseph Priestley. Priestley deploys the rhetoric of Newtonian natural philosophy in his writings on free will, and seeks to establish that necessitarianism is the only position compatible with a ‘scientific’ approach to human action.

Keywords: Hartley, Tucker, Priestley, Newton, associationalism, necessity, motives, providence,