This is Truth pulling out the tongue of falsehood after ripping off its mask. It's companion piece is Valour defeating cowardice. The bronzes for these sculptures by Alfred Stevens are part of the Monument to the Duke Of Wellington in St. Paul's Cathedral in London.
Personally, I think it is grotesque and horrible to show truth doing anything as violent as this. Maybe it is a reflection of the times (the 1850s) and perhaps a reflection of the military career of the Duke of Wellington. But I still think it is horrible.
How about truth teaching falsehood in a friendly way, with a smile?