Reflections on the asymmetry of causation

Abstract

The most immediately salient asymmetry in our experience of the world is the asymmetry of causation. In the last few decades, two developments have shed new light on the asymmetry of causation: clarity in the foundations of statistical mechanics, and the development of the interventionist conception of causation. In this paper, we ask what is the status of the causal arrow, assuming a thermodynamic gradient and the interventionist account of causation? We find that there is an objective asymmetry rooted in the thermodynamic gradient that underwrites the causal asymmetry: along a thermodynamic gradient, interventionist causal pathways—scaffolded intervention-supporting probabilistic relationships between variables—will propagate influence into the future, but not into the past. The reason is that the present macrostate of the world, in the presence of a low entropy boundary condition, will screen off probabilistic correlations to the past. The asymmetry, however, emerges only under the macroscopic coarse-graining and that raises the question of whether the arrow is simply an artefact of the macroscopic lenses through which we see the world. The question is sharpened and an answer proposed.

Making and breaking symmetries in mind and life

“…Finally, we come full circle, examining the question of how there may be space for our meanings in the physical world [114]. In 'Reflections on the asymmetry of causation', Jenann Ismael [115] helps to guide us through a vision in which scientific understanding and the 'manifest image' may be not just reconcilable [16,116], but mutually enriching. She begins by reminding us how causation is a paradigmatic example of an objective worldly relation, even the fundamental ordering relation of the world.…”