Chapter 5 gives a detailed account of the trial and execution of Thomas Aikenhead in Edinburgh in 1696–7. The statements that Aikenhead was accused of making are itemised, and their incendiary and openly blasphemous quality is clear. It is also noteworthy that he made such statements in public and seemed reluctant to retract them. This explains the harsh penalty to which he was subjected, which was the subject of much comment at the time. The case also attracted interest in England, not least from John Locke, who preserved various key documents relating to it. Here, Aikenhead’s sources are investigated, including the dangerous books to which he had access in the university library and elsewhere, and his ingenuity in constructing an irreligious ‘system’ from them is asserted.