Not only is the Cathedral of St. Mungo, or Glasgow Cathedral as it is more commonly known, the oldest surviving building in the city, but it is also the longest-standing house of worship in the Scottish mainland. Founded towards the end of the 12th century, it has seen its fair share of visitors, with an average yearly footfall of around 500,000.

Just opposite the Glasgow Necropolis, the city's sprawling Victorian-era cemetery, an inquisitive investigator may stumble upon a collection of vandalistic inscriptions on the northeastern outside corner of the building. Besides the common and usual use of names, or initials, combined with dates is a series of sentences that appear to be the handiwork of several separate individuals. Not even the caretakers of the cathedral are certain who or what the writings pertain to. 

What has been deciphered is that there appears to be a back-and-forth exchange of ideas. One of the carved writings states; "The Philosopher says, ' When death is, we are not: the body dies and with it all . . ."'. This is followed by a rebuttal from an unknown source, which has been attributed to either the French satirist Voltaire (1694 - 1778) or some other Roman philosopher. 

There then seems to be a third exchange containing words by Joseph Addison, (1672 - 1719) an English essayist.  Though unsubstantiated, this theological disagreement has been attributed to students attending the nearby Glasgow University. Whether the true identities will ever be revealed, or the reasons behind their acts of vandalism proven, they remain a centuries old delightful mystery.