Michael Kirby is a sculptor who champions many of the new movements within the performing arts, principally those which have been influenced by the chance methodology or sensibility of John Cage. Kirby's first book, Happenings, was a more or less descriptive summary of the most relevant examples of the genre, an informative record of theatre pieces by Kaprow, Whitman, Oldenburg, et al., a participant's survey of ""alogical"" and ""non-matrixed activity."" The Art of Time is again concerned with the avant garde (Environmental Theatre, Mixed-Media, the dance patterns of Deborah Hay, kinetic sculpture, empathy theory); but being a collection of randomly related articles and unconcerned with ""value judgments of artistic worth,"" the book tends to sound overly partisan and scrappy. Kirby exemplifies here much of the trouble with non-critical or non-analytic approaches to the arts since he uses a specialized form of discourse that can only have meaning to those intimately connected with Off Off-Broadway events. Those who have never experienced the multi-focus stage or ""objective dance,"" or are unaware of the crises going on now between the traditionalists and the experimentalists, can only react in a bemused state to Kirby's basically propagandistic stance. What is really wanted, and what is lacking even in Kirby's occasional theoretical forays, is an historical assessment of the ""new"" and ""impure"" art, so that the changing modes can be given a rationale or perspective.