The origins of his most iconic phrase were revealed in "Catch-22" where he got in a fight with Campbell, a man who introduced him to a woman played by Sonya Walger.  He's able
The origins of his most iconic phrase were revealed in "Catch-22" where he got in a fight with Campbell, a man who introduced him to a woman played by Sonya Walger.  He's able to save a bartender from getting hit in the head with a cricket bat by Jimmy Lennon after realizing he can change this future, and he also served as the replacement of Radzinsky.  This owner of the Elizabeth is prevented from buying a ring by Mrs. Hawking and at one point finds a letter from his long-lost love in a copy of Our Mutual Friend; that woman became his "constant" after he started having flashes following The Incident in the Hatch.  Played by Henry Ian Cusick, for 10 points, name this Lost character who spent much of Season 3 looking for Penny, and who shares his name with the author of An Enquiry Concerning Human Understanding.
The origins of his most iconic phrase were revealed in "Catch-22" where he got in a fight with Campbell, a man who introduced him to a woman played by Sonya Walger.  
{Desmond David Hume} [accept either underlined answer]