The irreducibility of complexity/limits to reductionism – Aristotle to Smuts to Einstein

In all things which have a plurality of parts, and which are not a total aggregate but a whole of some sort distinct from the parts, there is some cause ; inasmuch as even in bodies sometimes contact is the cause of their unity, and sometimes viscosity or some other such quality.But a definition is one account, not by connection, like the Iliad , but because it is a definition of one thing.
(Aristotle Metaphysics book 8 1045a)

Holism (from ὂλος holos, a Greek word meaning all, whole, entire, total) , is the idea that natural systems (physical, biological, chemical, social, economic, mental, linguistic, etc.) and their properties, should be viewed as wholes, not as collections of parts. This often includes the view that systems somehow function as wholes and that their functioning cannot be fully understood solely in terms of their component parts.
(Barry Oshry, Seeing Systems: Unlocking the Mysteries of Organizational Life, Berrett-Koehler Publishers, 2008 and Sunny Y. Auyang, Foundations of Complex-system Theories: in Economics, Evolutionary Biology, and Statistical Physics, Cambridge University Press, 1999)

After Einstein studied “Holism and Evolution” soon upon its publication, he wrote that two mental constructs will direct human thinking in the next millennium, his own mental construct of relativity and Smuts’ of holism. In the work of Smuts he saw a clear blueprint of much of his own life, work and personality.
(Letter from Einstein to Smuts, 24 June 1936, Vol 54, Folio 33, Cambridge University Library)

Phenomena such as emergence and work within the field of complex systems theory pose limits to reductionism. Stuart Kauffman is one of the advocates of this viewpoint, an American theoretical biologist and complex systems researcher who studies the origin of life on Earth. He is best known for arguing that the complexity of biological systems and organisms might result as much from self-organization and far-from-equilibrium dynamics as from Darwinian natural selection.