Are there philosophers who argue that thermodynamics (where time does have a direction) is the more fundamental theory as opposed to normal Newtonian mechanics and it's extensions?

For example, I can make consistent and coherent arguments that low entropy of the universe should not be surprising:


  • 3
    Do you mean modern statistical mechanics or classical thermodynamics? Classical thermodynamics is an extension of Newtonian mechanics; StatMech works even where Newtonian mechanics is completely useless.
    – g s
    Commented Jul 2, 2023 at 16:18
  • “It is the only physical theory of universal content, which I am convinced, that within the framework of applicability of its basic concepts will never be overthrown.” - Einstein on thermodynamics
    – CriglCragl
    Commented Jul 2, 2023 at 16:24
  • @gs not really imo ... physics.stackexchange.com/a/391382/150174 ; physics.stackexchange.com/a/47644/150174 Commented Jul 2, 2023 at 16:25
  • Do you mean StatMech and not really agree with my second sentence, classical thermodynamics and not really agree with my second sentence, or not really either?
    – g s
    Commented Jul 2, 2023 at 16:45

2 Answers 2


The relationship between thermodynamics and classical mechanics is that thermodynamics describes the statistical properties of particles using classical mechanics and is often seen as interrelated with mechanics such as Carnot's work on engines which talks about how temperature gradients lead to mechanical work. Another example is an average measure of kinetic energy of a collection of particles which is used to define heat as a statistical measure of energy flowing across materials. The relationship between the theories of thermodynamics and the theories of classical mechanics is that classical mechanics may help explain and show that human perception constructs emergence. So, when you ride in a hot air balloon, and rise into the atmosphere the Netwonian motion that describes your ascent in the craft can be understood in the Netwonian motion of the particles of air inside and outside of the air.

From the perspective of philosophy of science, this means that in some ways Newtonian mechanics is more fundamental than thermodynamics because the mathematical relationships of the former can be used to describe the latter. But in some ways, it is not more fundamental, because concepts like entropy, enthalpy, and free energy are emergent properties that are not inherent to individual particles themselves and the topic begins to enter the domain of chemistry which emerges from physics, but is not reducible to it entirely. As for the arrow of time, this is seen as a function of the second law of thermodynamics. A really good explanation about entropy of thermodynamics can be seen on the Veritasium channel on YT.

  • I really don't get why physicists are so hyped up on inflation. If one holds the view " it is not more fundamental, because concepts like entropy, enthalpy, and free energy are emergent properties" then it's a poorly motivated programme. Surely someone has pointed this out to them ... And I was hoping I could read his/her works Commented Jul 2, 2023 at 16:42
  • @MoreAnonymous I'd say that cosmological inflation is seen as an all-encompassing framework for explaining how everything relates... fundmentally, space-time, if is understood as a real thing, can derive explanation from a number of thermodynamic properties. Think about it. In the Great Chain of Being, God was the ultimate cause of everything. But in physics, where the supernatural isn't accepted, there still are the same questions, the same why's. Cosmic inflation answers those.
    – J D
    Commented Jul 2, 2023 at 16:46
  • Max Jammer may interest you.
    – J D
    Commented Jul 2, 2023 at 16:47
  • 1
    He does books like Concepts of Mass in Contemporary Physics
    – J D
    Commented Jul 2, 2023 at 16:48
  • I think physicists are more interested, not in the fact that there science is more fundamental than the rest of the hard sciences, but because they are pursuing the very notions of 'why does anything happen?' and 'where does it all come from?'. That is there are very existential and religious overtones to mathematical physics.
    – J D
    Commented Jul 2, 2023 at 16:50

What is the meaning of the term more fundamental in this context?

The reason thermodynamics might be considered more fundamental is that it accounts for the observation that the actual system and its surroundings cannot both be restored to the initial conditions via a reversible process.

The reason Newtonian physics might be considered more fundamental is because it gives us the foundational theoretical concepts for system analysis and the comprehension of an ideal reversible process.

Reversible and Irreversible Processes


An irreversible process is what we encounter in reality almost all the time. The system and its environment cannot be restored to their original states at the same time. Because this is what happens in nature, it is also called a natural process. The sign of an irreversible process comes from the finite gradient between the states occurring in the actual process. For example, when heat flows from one object to another, there is a finite temperature difference (gradient) between the two objects. More importantly, at any given moment of the process, the system most likely is not at equilibrium or in a well-defined state. This phenomenon is called irreversibility.


I removed prior references and comments.

  • "More fundamental" is usually taken to mean "capable of explaining". For instance, biochemistry is more fundamental than genetics, because nucleic acids, the building blocks of the chromosomes, are biochemical primitives. G, A, T, C, and U are themselves built from the primitives of atoms, thus, atoms are more fundamental than biomolecules, because biomolecules are composed of atoms, etc.
    – J D
    Commented Jul 2, 2023 at 16:40
  • The second "law" of thermodynamics, that entropy increases, isn't even true. Instead, it is true an overwhelmingly large fraction of the time. But it is still only a statistical law, which is explained by the ultramicroscopic motion of molecules. Commented Jul 11, 2023 at 3:58
  • @DanialAsimov At the molecular level, entropy is related to disorder. But the original definition of entropy is macroscopic, it is the heat transferred in a reversible process divided by the temperature at which the transfer occurs. This definition comes from thermodynamics, a classical, macroscopic theory, part of whose great power comes from the fact that it is developed without specifying the molecular nature of heat and temperature. Originally, entropy had no specific relation to order and had units of energy over temperature, such as J.K−1. newt.phys.unsw.edu.au/~jw/entropy.html Commented Jul 11, 2023 at 15:15
  • SystemTheory: Good points, but I don't believe they call into question what my comment claimed. Commented Jul 13, 2023 at 21:46
  • @DanielAsimov - To my knowledge the claims in your comment should be called into question. First, statistical analysis was not used historically to establish the second law of thermodynamics. Second, statistical analysis is coherent with the original statement of the second law. Third, empirical evidence does not appear to be available to show a violation of entropy increase in system and surroundings or closed system even on a statistical basis. These claims seem to be speculative not empirical demonstrations. Commented Jul 14, 2023 at 16:50

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