Mumford was also a contemporary and friend of Frank Lloyd Wright, Clarence Stein, Frederic Osborn, Edmund N. Bacon, and Vannevar Bush.

[5] Mumford was a close friend of the psychologist Henry Murray, with whom he corresponded extensively from 1928 until the 1960s on topics including Herman Melville, psychology, American values and culture, and the nature of the self.

His early architectural criticism helped to bring wider public recognition to the work of Henry Hobson Richardson, Louis Sullivan and Frank Lloyd Wright.

"[citation needed] In The Myth of the Machine Vol II: The Pentagon of Power (Chapter 12) (1970), Mumford criticizes the modern trend of technology, which emphasizes constant, unrestricted expansion, production, and replacement.

Modern technology, which he called "megatechnics," fails to produce lasting, quality products by using devices such as consumer credit, installment buying, non-functioning and defective designs, planned obsolescence, and frequent superficial "fashion" changes.

"[citation needed] He uses his own refrigerator as an example, reporting that it "has been in service for nineteen years, with only a single minor repair: an admirable job.

Slag heaps, poisoned waters, parking lots, and concrete cities, for example, are extremely limited in terms of their bioviability.

[14] Mumford believed that biotechnic consciousness (and possibly even community) was emerging as a later stage in the evolution of Darwinian thinking about the nature of human life.

In Mumford's understanding, the various technologies that arose in the megatechnic context have brought unintended and harmful side effects along with the obvious benefits they have bequeathed to us.

He points out, for example, that the development of money (as a technology) created, as a side effect, a context for irrational accumulation of excess because it eliminated the burdensome aspects of object-wealth by making wealth abstract.

Rather than the megatechnic pursuit of power, the biotechnic society would pursue what Mumford calls "plenitude"; that is, a homeostatic relationship between resources and needs.

In Mumford's words, a biotechnic society would direct itself toward "qualitative richness, amplitude, spaciousness, and freedom from quantitative pressures and crowding.

The reason is clear in the last sentence of The Pentagon of Power where he writes, "for those of us who have thrown off the myth of the machine, the next move is ours: for the gates of the technocratic prison will open automatically, despite their rusty ancient hinges, as soon as we choose to walk out."

[15] A key idea, introduced in Technics and Civilization (1934) was that technology was twofold: Mumford commonly criticized modern America's transportation networks as being "monotechnic" in their reliance on cars.

Automobiles become obstacles for other modes of transportation, such as walking, bicycle and public transit, because the roads they use consume so much space and are such a danger to people.

Mumford explains that the thousands of maimed and dead each year as a result of automobile accidents are a ritual sacrifice the American society makes because of its extreme reliance on highway transport.

The most recent megamachine manifests itself, according to Mumford, in modern technocratic nuclear powers—Mumford used the examples of the Soviet and United States power complexes represented by the Kremlin and the Pentagon, respectively.

He explains that meticulous attention to accounting and standardization, and elevation of military leaders to divine status, are spontaneous features of megamachines throughout history.

He also cites the overwhelming prevalence of quantitative accounting records among surviving historical fragments, from ancient Egypt to Nazi Germany.

According to Mumford, technological improvements such as the assembly line, or instant, global, wireless, communication and remote control, can easily weaken the perennial psychological barriers to certain types of questionable actions.

One of the better-known studies of Mumford is of the way the mechanical clock was developed by monks in the Middle Ages and subsequently adopted by the rest of society.

Harshly critical of urban sprawl, Mumford argues that the structure of modern cities is partially responsible for many social problems seen in western society.

Mumford wrote critically of urban culture believing the city is "a product of earth ... a fact of nature ... man's method of expression.

Mumford wrote: "The physical design of cities and their economic functions are secondary to their relationship to the natural environment and to the spiritual values of human community.

"[18] Suburbia did not escape Mumford's criticism either: In the suburb one might live and die without marring the image of an innocent world, except when some shadow of evil fell over a column in the newspaper.

[25] Ramachandra Guha noted his work contains "some of the earliest and finest thinking on bioregionalism, anti-nuclearism, biodiversity, alternate energy paths, ecological urban planning and appropriate technology.