According to Thomas Reid, the development of natural sciences following the model of Newton's Principia and Optics would provide further evidence for the belief in a provident God. This project was still supported by his student, Dugald Stewart, in the early nineteenth century. John Fearn , an early critic of the Scottish common sense school, thought that the rise of ‘infidelity’ in the wake of scientific progress had shown that the apologetic project of Reid and Stewart had failed. In reaction (...) to Reid and Stewart, he proposed an idealist philosophy that would dispense with the existence of matter, and would thus cut at the root what he thought was the main source of modern atheism. In this paper, I consider Fearn's critique of Reid and Stewart in his main works: First Lines of the Human Mind and Manual of the Physiology of Mind . I also consider Fearn's arguments against Hume and in favour of a renewed apologetics in An Essay on the Philosophy of Faith and the Economy of Revelatio.. (shrink)