American sculptor and writer on art. Born in Excelsior Springs, Missouri. Studied at the Art Students League, New York, 1948 and at the College of William and Mary, Williamsburg, 1948-9; later took degree courses in philosophy 1949-53 and then art history 1957-62 at Columbia University. First one-man exhibition at the Panoras Gallery, New York, 1957. 1959-65 a contributing editor to Arts Magazine and reviewer for Art News and Art International. Began as a painter, his paintings developing in the early 1960s into low-reliefs, then into high-reliefs and free-standing works. Made wall pieces and floor pieces with precise geometrical forms and without a base. His earliest sculptures were mainly in wood, but after his exhibition at the Green Gallery, New York in 1963-4, which established his reputation, he began to have his pieces fabricated from his designs in metal and sometimes coloured perspex. Lives in New York.