If you look at _any_ complex event (war , disease , great success , great failure) you can use the same rule of thumb. As an example, did Europe in the middle a

If you look at _any_ complex event (war , disease , great success , great failure) you can use the same rule of thumb. As an example, did Europe in the middle ages succeed only because of science and technology? Did they take more risks because they could get credit? It's all layers and makes for a richer understanding of the world :)