The criterion sounds simple until one tries to apply it. A tool's appropriateness cannot be read off its specifications. It can only be judged by attending to what the tool does to the person who uses it, and that attention requires the most demanding kind of observation—observation of one's own experience over time, including the periods when the tool is not in use.
Claude Code at one hundred dollars a month places sophisticated computing within reach of most knowledge workers. It is eminently suitable for small-scale application: a single person uses it without a team, a manager, or an IT department. And the natural language interface is, by any historical measure, the most creativity-compatible computing interface ever built. Every previous interface imposed a translation tax. This one does not.
But appropriateness must be evaluated at both scales: the scale of the task and the scale of the life. The tool is always available. It does not have office hours. It does not tire. It does not suggest a break. The natural friction of human collaboration—the colleague's unavailability, the meeting that imposes a pause, the commute that creates a boundary—is absent. The tool removes friction from the work, and the friction it removes includes friction that the worker needed.
This is where Schumacher's criterion cuts against the grain of what the AI industry considers success. A more powerful tool is not automatically a more appropriate tool. Ascending friction describes what remains; appropriate technology asks whether what remains is enough.
The concept emerged from Schumacher's observations in developing economies during the 1950s and 1960s. He watched powerful industrial technology arrive in communities that lacked the infrastructure to absorb it, producing dependence rather than development. The intermediate option—tools more productive than traditional methods but simpler than industrial alternatives—was his structural response.
Three criteria. Cheap and accessible, suitable for small-scale use, compatible with creative engagement—non-negotiable and jointly required.
Creativity-compatible interface. The natural language interface abolishes the translation tax that every previous computing tool imposed, leaving the builder's judgment in charge at the conceptual level.
Evaluation at two scales. A tool may be appropriate within the task and inappropriate within the life. Always-on availability converts possibility into compulsion.
Self-limiting principle. Technology recognizes none; limits must come from outside—from the worker, the community, or institutional structures.