Ivan Illich was a prominent social critic who was quite skeptical of unfettered technological advancement and modernization. To articulate his points, he leans on the concepts of thresholds and conviviality, which have become core concepts for the global degrowth community. Illich believed that technology and social processes have limits to their benefit, and that they can become dangerous, and even destructive, if left unchecked. He illustrates the concept of thresholds using a snail:

“A snail, after adding a number of widening rings to the delicate structure of its shell, suddenly brings its accustomed activities to a stop. A single additional ring would increase the size of the shell sixteen times. Instead of contributing to the welfare of the snail, it would burden the creature with such an excess of weight that any increase in its productivity would henceforth be literally outweighed by the task of coping with the difficulties created by enlarging the shell beyond the limits set by its purpose.”

The snail recognizes that there is a threshold for the shell, after which any further growth would become detrimental to the snail’s wellbeing. Degrowth uses the snail as its international symbol to articulate this point, that limits must be placed on technology, social processes, and certain activity, to facilitate wide-spread and lasting wellbeing for human and non-human life.