Synergy is an interaction or cooperation giving rise to a whole that is greater than the simple sum of its parts. The term synergy comes from the Attic Greek word συνεργία synergia from synergos, συνεργός, meaning "working together".
In Christian theology, synergism is the idea that salvation involves some form of cooperation between divine grace and human freedom.
The words synergy and synergetic have been used in the field of physiology since at least the middle of the 19th century:
SYN'ERGY, Synergi'a, Synenergi'a, (F.) Synergie; from συν, 'with', and εργον, 'work'. A correlation or concourse of action between different organs in health; and, according to some, in disease.
—Dunglison, Robley Medical Lexicon Blanchard and Lea, 1853
In 1896, Henri Mazel applied the term "synergy" to social psychology by writing La synergie sociale, in which he argued that Darwinian theory failed to account of "social synergy" or "social love", a collective evolutionary drive. The highest civilizations were the work not only of the elite but of the masses too; those masses must be led, however, because the crowd, a feminine and unconscious force, cannot distinguish between good and evil.
In 1909, Lester Frank Ward defined synergy as the universal constructive principle of nature:
I have characterized the social struggle as centrifugal and social solidarity as centripetal. Either alone is productive of evil consequences. Struggle is essentially destructive of the social order, while communism removes individual initiative. The one leads to disorder, the other to degeneracy. What is not seen—the truth that has no expounders—is that the wholesome, constructive movement consists in the properly ordered combination and interaction of both these principles. This is social synergy, which is a form of cosmic synergy, the universal constructive principle of nature.
—Ward, Lester F. Glimpses of the Cosmos, volume VI (1897–1912) G. P. Putnam's Sons, 1918, p.