Convergent discovery reflects the adjacent possible — ideas become findable when preconditions ripen

Stuart Kauffman’s adjacent possible describes the set of configurations one step from the current state. Each innovation reshapes the boundary. When preconditions align, the same discovery becomes reachable from multiple starting positions — explaining why Darwin/Wallace, Newton/Leibniz, and Campbell converged independently. The framework applies recursively to policy proposals.

Explanandum

Why do independent researchers in different fields sometimes formulate nearly identical ideas at nearly the same time? Is this coincidence, or does it reflect something structural about the space of possible ideas?

Substance

Kauffman’s original biological concept describes how each innovation opens new doors while closing others. Steven Johnson popularised it for intellectual history. Robert Merton studied “multiples” — simultaneous independent discoveries — and argued they are the norm rather than the exception in science.

The Campbell convergence illustrates the mechanism: by the mid-1970s, decades of technocratic governance had created the preconditions for recognising that metrics fail when used as targets. Campbell (social psychology) and Goodhart (monetary economics) reached the same insight from different starting positions because they were both standing at the edge of the same adjacent possible.

The framework applies to the three Works in Progress articles themselves. Better competition metrics are adjacent-possible now because firm-level data is becoming available and computational methods are mature. Water-based geopolitical arguments are possible because solar costs have crossed the viability threshold. Land readjustment advocacy is possible because the housing crisis has made previously unthinkable reforms enter policy conversation. Each proposal reaches as far as current preconditions allow — and no further.

Supports

• Darwin and Wallace, Newton and Leibniz, Elisha Gray and Bell: canonical multiples
• Merton’s systematic study showed multiples are more common than singletons in the history of science
• The 1970s “triple” of Goodhart, Campbell, and Lucas, all expressing variants of the same insight from different disciplines

Challenges

• The framework may be unfalsifiable — any convergence can be explained as “conditions were ripe” after the fact
• Priority disputes matter for incentives even if the adjacent possible makes convergence likely
• Some genuinely singular discoveries (general relativity?) may resist the framework

Open Questions

• Can the adjacent possible be mapped prospectively — predicting which ideas are about to become discoverable?
• Does the framework help identify which policy proposals are “ripe” for adoption versus premature?

Source Context

Invoked to explain the Goodhart/Campbell convergence, then applied recursively to the three articles’ proposals.