Mumford believed that what defined humanity, what set human beings apart from other animals, was not primarily our use of tools (technology) but our use of language (symbols).

Mumford's general view of religion is that it is a valid and invaluable variety of experience and he wants to incorporate it into the regimen of men of the future, but he himself, it seems to me, is not religious and does not look upon religious insight as necessarily the highest insight.

According to Mumford in fact, the primary function of the city is to transform power into form, energy into culture, dead matter into living symbols of art, biological reproduction into social creativity.

In 1937, Lewis Mumford, one of the greatest historians of cities in the 20th century, wrote an influential essay entitled “What Is a City?” in which he argued that cities should primarily be considered as social institutions rather than physical artefacts.