Untitled (Pink Felt) Cat Nest, 1970, felt pieces of various sizes (for cats), overall dimensions variable. Soft and mutable, rather than hard and fixed “primary structures” à la Judd, this work is technically “post-Minimalist” but still cat-friendly. In Notes on Sculpture (1966) Morris wrote: “Minimalism is not concerned with the work of art itself, but, rather, focuses on the conditions in which it is viewed by a spectator.
Richard Kalina in Art in America magazine (December 31, 1969,) summarized a general significance of Robert Morris this way:
The focus on matter and gravity as means results in forms that were not projected in advance. Considerations of ordering are necessarily casual and imprecise and unemphasized. Random piling, loose stacking, hanging, give passing form to the material. Chance is accepted and indeterminacy is implied, as replacing will result in another configuration. Disengagement with preconceived enduring forms is a positive assertion. It is part of the work’s refusal to continue estheticizing the form by dealing with it as a prescribed end.
Of course with cats, "indeterminacy is implied" is a given.