Index 01 is radical, but it doesn’t exist in a complete vacuum. There are three examples I would contrast with Index 01, the latter two of which are contemporary with it.
Marcel Duchamp’s “The Bride Stripped Bare By Her Batchelors, Even (The Large Glass)” predates Index 01 by some sixty years. It is a free-standing painting in metal and oil paint on glass, about as painterly as a set of filing cabinets. The forms in it were determined by Duchamp’s writings and were produced in a series of studies before being assembled in The Large Glass. Like Index 01 is a combination of forms determined by writing. It is a form of index, an assemblage of forms whose relations embody conceptual concerns. The Large Glass is the embodiment of its index rather than the indexical relations of the work being explained by texts placed on the wall, and the texts are elsewhere.
Sol LeWitt’s drawings have a similar concern with platonic form, although they are more immediately aesthetic than Index 01. LeWitt’s drawings constructed from verbal descriptions, whether colours or coloured shapes or geometric shapes constructed according to constraints, are conceptually determined forms. They are more aesthetic than Index 01, but they do construct form conceptually. Like Index 01 and The Large Glass the text precedes and creates the form of “the work”. The platonism of this is critical, it is a line of resistance.
Gilbert and George’s work as living sculptures is arch- (and arch) romanticism rather than analytical philosophy and politics or sociology, but it has commonalities with Index 01. Gilbert and George substituted social form for sculptural form, declaring themselves sculpture. Body rather than text, and romantic conservatism rather than materialist radicalism, but non-aesthetic form expressed socially. The “singing sculptures” are the negative of Index 01, the defensible and resistant production of form in an ironically conservative mode.
I don’t expect that Art & Language would find these comparisons flattering or interesting. But I believe that they provide at least an interesting contrast, and that they may be instructive.