For my generation, Judd posed the same problem as Picasso did for the Abstract Expressionists; you either had to go over, under, around, or through him. Conceptual, process, and Earth Art, each in their own way, constituted a rejection of the 'specific object'.
Mel Bochner (2005, p. 70) in: David Raskin. Donald Judd. New Haven: Yale University Press, 2010.