[nasamn777]

The mechanism can be treated as a black box, which is one of the uses of thermodynamics. It can also be used to analyze the mechanism. The reality is that you need a mechanism to go from state 1 (p1,v1,T1) to state 2(p2,v2,T2) -- except in rare circumstances (e.g. natural weather conditions). Also, the notion of reversibility has everything to do with the mechanism. To allow the change typically you have to apply work that is constrained in specialized ways enabling the process to occur. The mechanism is the device that constrains the energy.

[aNYCguy]

The mechanism can be treated as a black box, which is one of the uses of thermodynamics. It can also be used to analyze the mechanism. The reality is that you need a mechanism to go from state 1 (p1,v1,T1) to state 2(p2,v2,T2) -- except in rare circumstances (e.g. natural weather conditions).

You said earlier something like "I work in one of the sciences related to thermodynamics." I'm curious: which field are you educated in, and which are you working in, if the two are diffent?