A 1935 summary of Lawrence Henderson, amid the Harvard Pareto circle and "Sociology 23" lectures, summarizing that the the central feature of Vilfredo Pareto's 1912 general sociology is the modeling of a social system similar or framed akin to to Willard Gibbs' physiochemical system of chemical thermodynamics, i.e. "system" of thermodynamics with the addition of chemical potential of boundary crossing or system additions or substractions; akin to a van't Hoff equilibrium box model of society, with semi-permeable boundries [2]

“The comprehension of the laws which govern ANY material system is greatly facilitated by considering the energy and entropy of the system in the various states of which it is capable.”

— Willard Gibbs (1876), On the Equilibrium of Heterogeneous Substances

“Any arbitrarily isolated portion of the material universe, according to Gibbs, may be regarded as a physico-chemical system.”

— Lawrence Henderson (1935), “Physician as Patient and as a Social System” [3]

“Gibbs’ physico-chemical system, Henderson felt, validated the concept of a system as a genuine abstraction, useful despite the fact that it was a creation of the imagination. Systems imposed boundaries and mapped out relationships: within them, facts made sense. They were ordered and interrelated. They became amenable to logical consideration. [Henderson wrote]: ‘Just as Newton first conclusively showed that this is a world of masses, so Gibbs showed revealed it as a world of systems.’”

— Cynthia Russett (1966), The Concept of Equilibrium in American Social Thought [1]