So what makes a tool “convivial?” For Illich, “tools foster conviviality to the extent to which they can be easily used, by anybody, as often or as seldom as desired, for the accomplishment of a purpose chosen by the user.” That is, convivial technologies are accessible, flexible, and noncoercive. Many tools are neutral, but some promote conviviality and some choke it off. Hand tools, for Illich, are neutral. Illich offers the telephone as an example of a tool that is “structurally convivial” (remember, this is in the days of the ubiquitous public pay phone): anyone who can afford a coin can use it to say whatever they want. “The telephone lets anybody say what he wants to the person of his choice; he can conduct business, express love, or pick a quarrel. It is impossible for bureaucrats to define what people say to each other on the phone, even though they can interfere with — or protect — the privacy of their exchange.”

A “manipulatory” tool, on the other hand, blocks off other choices. The automobile and the highway system it spawned are, for Illich, prime examples of this process. Licensure systems that devalue people who have not received them, such as compulsory schooling, are another example. But these kinds of tools, that is, large-scale industrial production, would not be prohibited in a convivial society. “What is fundamental to a convivial society is not the total absence of manipulative institutions and addictive goods and services, but the balance between those tools which create the specific demands they are specialized to satisfy and those complementary, enabling tools which foster self-realization.”

— Why the Landline Telephone Was the Perfect Tool – Suzanne Fischer