Counterproductivity
The main notion of Ivan Illich is the concept of counterproductivity: when institutions of modern industrial society impede their purported aims. For example, Ivan Illich calculated that, in America in the 1970s, if you add the time spent to work to earn the money to buy a car, the time spent in the car (including traffic jam), the time spent in the health care industry because of a car crash, the time spent in the oil industry to fuel cars ...etc., and you divide the number of kilometres traveled per year by that, you obtain the following calculation: 10000 km per year per person divided by 1600 hours per year per American equals 6 km per hour. So the real speed of a car would be about 3.7 miles per hour.
Specific diseconomy
Specific diseconomy is another term Illich used, as a measure of the degree of institutional counterproductivity that is occurring—referring to the exact degree to which, for example, the medical industry induces illness, educational institutions induce ignorance, the judicial system perpetuates injustice, or national defense may make a nation less secure. When specific diseconomy is on the increase, this means an institution or industry is increasingly counterproductive to its original intentions.
Radical monopoly
He invented the concept of radical monopoly: when a technical medium is or appears to be more effective, it creates a monopoly which denies access to other media. The mandatory consumption of a medium which uses a lot of energy (for example motorised transportation) narrows the fruition of use value (innate transit ability).
By "radical monopoly" I mean the dominance of one type of product rather than the dominance of one brand. I speak about radical monopoly when one industrial production process exercises an exclusive control over the satisfaction of a pressing need, and excludes nonindustrial activities from competition.
—Ivan Illich, [19]
Conviviality
Illich worked to open new possibilities. Illich devotes a chapter of Deschooling Society to the proposal to the Rebirth of Epimethean Man.[20] He argued that we need convivial tools as opposed to machines. A tool may have many applications, some very different from its original intended use. A tool may be thought of as an expression of its user. The opposite of this is the machine, where humans become its servants, their role consisting only of running the machine for a single purpose.