This is an invited contribution to Comprehensive Philosophy of Science, Elsevier (2026)
I point out that a neglected principle of quantum mechanics provides a decisive defeat of the notorious “Maxwell’s Demon.” Comments welcome!
ABSTRACT: This work provides an overview of key historical developments in the formulation of the Second Law of Thermodynamics, focusing on the notorious challenge of “Maxwell’s Demon”, a hypothetical creature who could presumably violate that law. It begins by recalling Maxwell’s challenge and discussing the apparent loophole in the Second Law that appears to make such a violation possible. An alternative formulation of the Demon challenge by Szilard is considered, along with his attempted defeat of the Demon through reference to measurement. A similar effort by Brillouin is also analyzed. The more recent proposal of Bennett to defeat the Demon through the requirement of memory erasure is critically discussed. Finally, it is proposed that the Second Law gains a firm foundation through a neglected feature of quantum theory, namely the Heisenberg Uncertainty Principle, which also decisively serves to defeat the Demon.
Transactional Interpretation 