The Geometry of Vision To understand the impact of John Stephan, one must look past the surface of his later, disciplined abstractions and recognize a man who helped define the visual language of a movement. He was not a peripheral figure in the development of Abstract Expressionism; he was a central participant in the creative ferment of mid-century New York. His work moved from the urban landscapes and WPA-commissioned mosaics of the 1930s toward a rigorous, geometric precision that demanded a different kind of attention. He did not merely paint; he constructed visual systems. His contribut…