The sword issue is quite good. I especially like this quote: "Invasion may be a sword; but peaceful penetration is a poison." GKC wrote that in 1927, thereby diagnosing Europe's Muslim problem 75 years before it got sick.
I also liked this quote: "Truth is a two-edged sword, and we must always let it cut both ways." A person could cogitate on that one for hours (heck, a lifetime).
On airline security: "the pocket-knife is a secret sword." I just wish my boys could carry a pocket knife. There's something boyishly ennobling about it, but it's distinctly degrading to get expelled from school for it.
On modern marriage: "When men have left off wearing swords, women shall begin to wave them."