Quine's set theory and its background logic were driven by a desire to minimize posits; each innovation is pushed as far as it can be pushed before further innovations are introduced. For Quine, there is but one connective, the Sheffer stroke , and one quantifier, the universal quantifier . All polyadic predicates can be reduced to one dyadic predicate, interpretable as set membership. His rules of proof were limited to modus ponens and substitution. He preferred conjunction to either disjunction or the conditional , because conjunction has the least semantic ambiguity. He was delighted to discover early in his career that all of first order logic and set theory could be grounded in a mere two primitive notions: abstraction and inclusion . For an elegant introduction to the parsimony of Quine's approach to logic, see his "New Foundations for Mathematical Logic," ch. 5 in his From a Logical Point of View .
Duhem is also known for his work in thermodynamics, being in part responsible for the development of what is known as the Gibbs–Duhem relation and the Duhem–Margules equation . Duhem thought that from the first principles of thermodynamics physicists should be able to derive all the other fields of physics—., chemistry, mechanics, and electromagnetism.  Duhem, influenced by Macquorn Rankine 's "Outlines of the Science of Energetics",  carried out this project in Traité de l'Énergétique (1911) but was unable to subject electromagnetism to thermodynamic first principles.