In December 1793 Godwin sat down to read An Account of the Trial of Thomas Muir, Esq. The documented account of Muir's travails gripped his attention: he read all 160 pages in a single sitting. Later that day Thomas Holcroft called round for tea and the two friends discussed tyranny, a topic which Godwin recorded in his diary in Greek, possibly due to fears induced by Muir's experience. Muir was then in London along with his fellow convict, on the same charge of sedition, Thomas Palmer. They were awaiting transportation on a hulk in Woolwich. Although Woolwich represented about a ten mile journey, Godwin and Irish radical John Fenwick walked there to visit Muir. Over the next couple of days Godwin met with other radical figures like John Horne Tooke, John Thelwall, George Dyson and Holcroft. It seems probable that Muir's experience had a profound effect on Godwin. Not only was it a tale that permeated Caleb Williams, it also directly galvanized his writing of the novel which was stuttering at the time, generating the ‘afflatus’ that was necessary to his writing process. Moreover, three days after meeting him Godwin joined the Philomathean Society, or the Philomaths.

A Philomathmay be defined as a lover of learning. Henry Grove Amory, of solid Taunton Dissenting stock, founded the society, probably in the late 1780s.