One interesting comment made by Gabriel Syme was in reply to Gregory's question if it were true that Syme had a religion. Syme smiled and replied "we are all Catholics now".
This has me wondering what Chesterton meant. This novel was published in 1908 and Chesterton did not convert to Roman Catholisism untill 1922. Was Syme refering to being "catholic" in the "universal" sense? Or was it Roman Catholisism he was refering to since he did use a capital "C"?
Even more interesting that Gregory insists that Syme swear to whatever gods he belives in before showing him a secret.