 In Geneva on his continental tour Boyle underwent what he clearly felt to be a conversion from nominal or at least unthinking Christianity to committed Christianity. One summer night, he “was suddenly waked in a Fright with such loud Claps of Thunder … &amp; every clap … both preceded &amp; attended with Flashes of lightning so numerous … &amp; so dazling, that [he] began to imagine … the Day of Judgment’s being come.” This led him to vow that “all further additions to his life shud be more Religiously &amp; carefully employ’d.” Realizing the inefficacy of a promise exacted under duress, Boyle repeated the performance under a serene and cloudless sky “so solemnly that from that Day he dated his Conversion; renewing now he was past Danger, the vow he had made whilst he fancy’d himselfe to be in it: that tho his Feare was (&amp; he blush’t it was so) the … occasion of his Resolution of Amendment; yet at least he might not owe his more deliberate consecration … of himselfe to Piety, to any less noble Motive then that of it’s owne Excellence” (BP 37:181r-v, Hunter 1994a, 16).