The Mereology of Thermodynamic Equilibrium

TL;DR

This paper proposes a thermodynamic composition principle based on the minus first law of thermodynamics, suggesting that systems in thermal contact compose a single system, with formal analysis using mereotopology.

Contribution

It introduces the thermodynamic composition principle (TCP) derived from thermodynamics, providing a new approach to the special composition question in metaphysics.

Findings

The TCP is justified through classification of mereological models.

Formal analysis employs mereotopology and self-connectedness.

Supports inductive argument for universalism in composition.

Abstract

The special composition question (SCQ), which asks under which conditions objects compose a further object, establishes a central debate in modern metaphysics. Recent successes of inductive metaphysics, which studies the implications of the natural sciences for metaphysical problems, suggest that insights into the SCQ can be gained by investigating the physics of composite systems. In this work, I show that the minus first law of thermodynamics, which is concerned with the approach to equilibrium, leads to a new approach to the SCQ, the thermodynamic composition principle (TCP): Multiple systems in (generalized) thermal contact compose a single system. This principle, which is justified based on a systematic classification of possible mereological models for thermodynamic systems, can form the basis of an inductive argument for universalism. A formal analysis of the TCP is provided on the basis of mereotopology, which is a combination of mereology and topology. Here, "thermal contact" can be analyzed using the mereotopological predicate "self-connectedness". Self-connectedness has to be defined in terms of mereological sums to ensure that scattered objects cannot be self-connected.