4. General equilibrium theory in economics was shaped by Josiah Gibbs (the physicist Einstein called “the greatest mind in American history”). Gibbs invented statistical mechanics to describe the behavior of large aggregates like gases. An appealing metaphor since economies are also large aggregates? Well, the “invisible hand” equilibria of physics emerge from parts that interact utterly consistently. But people aren’t gas particles or biological billiard balls. We evolved behavioral flexibility. Our actions and reactions vary (complexly, often game-theoretically). 5. Newton’s science is metaphorically and structurally different than Darwin’s. Newton’s systems have closed causality and converge on mechanically calculable patterns. Physicists have good mathematical tools for predicting their specific results. But Darwin described open, generative, and divergent processes with less predictable outcomes. The shapes of these processes are stable, but their resulting “endless forms” aren’t as pre-calculable. Economics, though it loves physicsy-math-tools, has unavoidable evolution-like aspects (and evolutionists don’t find physicsy-math-models to be that useful). - bigthink.com