MORE THAN MOST EXHIBITIONS, “The Way of the Shovel: Art as Archaeology” aspires to give material form to a theoretical argument. Its curator, Dieter Roelstraete, has long been interested in the relation between art and historical excavation, and the show takes both impetus and title from a polemical essay he penned in 2009. This titular echo raises fundamental questions about the relationship between text and object, writing and digging: There is, indeed, a marked difference between Roelstraete’s verbal and curatorial formulations. Whereas the essay decried what he lamented as art’s “historiographic