Cutter, I suspect that the appeal of the blade originally came about as a secondary weapon from earlier eras of more limited shots, unreliable ignition, and etc. Early wheel lock and snaphaunce pistols incorporated a decorative ball on the butt that was intended to be used as a bludgeon once the pistol was discharged. Various combinations of swords and firearms also exist. While, by the pinfire era, it was probably more of a nifty afterthought than a practicality, the idea hung on. Late 19th Century breaktops also incorporated a small bayonettes (Harrington and Richardson made one as I recall) and most recently, CZ has marketed a bayonette for the CZ 75 SP that mounts on a 1913 (Picatinny) rail.Yes, that is a folding knife blade. What I have always wondered is what is the benefit of such a design other than having a pocket knife and a pistol in one handy package.