The “Equivalents” remain photography’s most radical demonstration of faith in the existence of a reality behind and beyond that offered by the world of appearances. They are intended to function evocatively, like music, and they express a desire to leave behind the physical world, a desire symbolized by the visual absence of horizon and scale clues within the frame. Emotion resides solely in form, they assert, not in the specifics of time and place.

— Andy Grundberg, 1983 on Alfred Stieglitz “Equivalents”