This paper analyses two key aspects of the life and work of Sir James Young Simpson: his evangelical Christianity and his reaction to criticism following his use of anaesthesia in obstetrics. Simpson's personal religious struggle is placed in the context of the devastating events surrounding the Disruption of the established Church of Scotland in 1843. Whatever his involvement in the events of that year, the development of his faith demonstrates his simple evangelical conviction in the atonement of Christ, very much in keeping with that of many believers in Victorian Britain. There has arisen the notion (still current as is clear from publications in medical journals within recent years) that there was a savage religious response, especially in Presbyterian Scotland, to his use of chloroform - in reality the attack on Simpson's enthusiastic promotion of chloroform was brief, sporadic and of little moment. Simpson's carefully constructed counter to criticism of anaesthesia, drawing on considerable theological and linguistic expertise, reveals a complexity at odds with the simplicity of his faith. The contrast is so great and the reaction so elaborate that it is proposed that Simpson deliberately exaggerated the affair, believing the publicity could only be valuable.