Aperspective is a technical term, introduced by Jean Gebser (1947-1965), to describe developments in twentieth century art involving modern physics and time as the fourth dimension. Saint- Martin attempted to classify these developments in modern art more precisely and has identified at least twelve different movements which she names: optical perspective, arabesque, focal, reversible, unistic, tachiste, chessboard, analytic and synthetic cubist, cavaliere and angular perspective.