Use a stepping-stone idea: an intermediate impossible idea

Generate a deliberately impractical intermediate idea to use as a bridge to a practical one you could not have reached directly.

Why it works

When reasoning within the space of feasible ideas, the mind is constrained by what is already known to work. An intermediate stepping-stone idea — explicitly impossible or impractical — temporarily extends the possibility space beyond feasibility, allowing the thinker to reach a vantage point from which a new, practical idea becomes visible. The stepping stone is discarded; the new vantage point is kept.

How to do it

1. State where you are stuck.
2. Generate an exaggerated, impractical version of the solution: one that would obviously work if cost, physics, or social acceptability were no obstacle.
3. From that extreme idea, "step back" toward feasibility: what is the closest practical version of this?
4. Repeat: step back again. What is practical about the step-back?
5. Evaluate the practical idea on its own merits — the stepping stone is no longer needed.

Evidence

The stepping-stone technique operationalizes a form of analogical distance: beginning from a distant or extreme conceptual position and converging toward a practical solution traverses a larger solution space than staying close to the feasible edge throughout. This is consistent with research on intermediate analogy and creative distance in problem solving. (mechanistic)

The specific stepping-stone format is de Bono’s; the underlying principle of using extreme ideas as cognitive scaffolding is consistent with but not isolated in direct experiments.

Common mistake

Getting attached to the stepping-stone idea and trying to make it feasible rather than using it as a bridge — the value is in where it takes your thinking, not in the idea itself.