Out of his experiences in the avant-garde art world of New York, Brockman's writings were quickly evolving. His first book, By The Late John Brockman (1969), was introduced in 1968 as part of a six-evening avant-garde event at The Poetry Center at the 92nd St Y in New York. Preceding and following Brockman on the programme, respectively, were evenings by John Cage and Jorge Luis Borges. This was the era of The Living Theatre, of Antonin Artaud's "theatre of cruelty", and the management of the Poetry Center had trepidation about Brockman's event—and rightly so. His "reading", a performance piece, orchestrated in collaboration with Ken Dewey's Theatre X and artist group USCO, was an attack on the values of the Poetry Center itself. The evening turned into a riotous affair—enraged audience members stopped the show five times, closing the curtains, stealing the scripts, harassing the performers, turning off the lights.

By The Late John Brockman, his second book, 37 (1971), and a third book intended as volume three of the trilogy, were published together in a paperback in 1973 under the title Afterwords. They were a response to the idea of cybernetics. The first book looks at all human theory through the lens of information theory; the second examines Heisenberg's theory of indeterminacy, and the third investigates the limits of words as tools for understanding.

When Heinz von Foerster, an architect of cybernetics along with Warren McCulloch, Norbert Wiener, and John von Neumann, reviewed the trilogy in 1973, he commented:

"Brockman takes the mystery of language and puts it right back into its own mystery; that is, he ex-plains the mystery of language by taking language out ('ex-') of the plane of its mystery, so as to become visible to all before it slips back into its plane. This in itself is a remarkable achievement that has been denied to almost all linguists, for they stick to the description of the plane without seeing that it is the plane that holds their descriptions … All who are concerned about the violence committed in the name of language will appreciate the useful uselessness of Brockman's un-book.".*

Von Foerster's appreciation of Brockman's writing is no surprise. While Brockman began writing his trilogy in 1966, von Foerster led a movement that began in 1968 to develop "2nd order cybernetics", or, "the cybernetics of cybernetics”. Von Foerster wrote in 1973: 

". . . a brain is required to write a theory of a brain. From this follows that a theory of the brain that has any aspirations for completeness has to account for the writing of this theory. And even more fascinating, the writer of this theory has to account for her or himself."

That year Gregory Bateson and Margaret Mead increasingly talked about patterns and processes, or "the pattern that connects". They called for a new kind of systems ecology in which organisms and the environment in which they live, or which they study, are one and the same. They were henceforth to be considered as a single circuit. It was only after Afterwords was published in early 1973 that Brockman met Bateson, Mead, and von Foerster. In April of that year, a group that included von Foerster, Bateson, Zen philosopher Alan Watts, and dolphin researcher John Lilly, convened the legendary AUM (American University of Masters) Conference in Big Sur to study G. Spencer Brown's book, Laws of Form. The premise of American University of Masters was that it was comprised of those maverick intellectuals whose authority derived from their persona, ideas and work, and not from their institutional affiliations. Brockman, on the strength of his trilogy, was summoned at the last minute to replace the keynote speaker Richard Feynman, who had been hospitalized.

Later, in a visit to Brockman in New York, Bateson told him "The cybernetic idea is the most important idea since Jesus Christ. And it's an idea that's foreign to almost every so-called intellectual among mainstream thinkers." However, it was an idea that was pervading the art world at this time. John Cage, for example, was interested in how ideas and patterns move through cultures, while Nam June Paik's videos were, in Brockman's words, "an example of the cybernetic idea in action". "The cybernetic idea was not about 'a' and 'b' ", he recalled; "it was about a process and the process was the reality." Each of his books is made as a process, performance or experience, recalling the Duchampian idea that the reader/viewer does at least fifty percent of the work. Brockman takes this idea even further in his belief that the reader owns the words, which makes his books highly performative in the moment of reading.

In this, his writing anticipated the ideas of Bateson and Mead concerning the necessity of considering the ecological nature of the organism and its environment as a single circuit. Brockman calls it "undifferentiated activity". "The entire work is performance piece that in all parts are the whole, undifferentiated as activity, where you can't tell who the subject is, you can't tell what the subject is.” To him, the writing is demanding, physical, and exhausting, requiring the reader to constantly keep in mind the complete work, i.e. the single circuit.

In the first edition of By The Late John Brockman, it is not only the content that is highly experimental, but also its format and layout. Each page contains a single paragraph comprised partly of quotes from works by figures from Marshall McLuhan to Ludwig Wittgenstein, Samuel Beckett and ee cummings, that is disconnected from its predecessor. A front-page review in the San Francisco Review of Books stated: 

"In short, sharp strokes of words, he breaks through the very forest of meaning by denying meaning, eschewing traditional forms of activities, thoughts and emotions. It is not what he says that is so valuable; it is his whole manner of negating what can be said. His words backtrack on themselves, stalk their own meanings, and thrash about in the underbrush of our sensibilities. There is a total devastation of language, isolating and withering the very hands our dreams are made of." *

Pre-empting the ebook by many decades – or conversely, recalling ancient scrolls – the first edition was printed on one side of the page only. Brockman had told his editor at Macmillan: "It is obscene to print on both sides of a page."

Although the reception to Afterwords in 1973 was decidedly mixed, comments when it was nominated for the long list of 10 books for the National Book Award, ranged from "Trashiest specimen of newly proliferating genre of electronic dada" (Kirkus), to "The best book since Wittgenstein's Tractatus" (Alan Watts); from "Terrifying … depressing … cerebral … icy" (Vogue), to "There are certain writers whose thought is so important that it doesn't matter whether you agree with them or not. A verbal tension so powerful, an ascetic appetite so huge and consuming forces us both to accept the vision as a revelation and to resist it as a duty." (San Francisco Review of Books ).