[4] Illich believed that past this critical threshold, the product of industry served to deprive people of their native ability to subsist, to learn, move and heal autonomously, leaving them more ignorant, isolated and sick than if industry had not reached beyond the threshold of overdevelopment. Decay in the human condition appears because under industrial overdevelopment, "people are trained for consumption rather than for action, and at the same time their range of action is narrowed." Counterproductivity has been called "probably Illich’s most original contribution".[5]