Editing Connectionism (section)

==Precursors==
Precursors of the connectionist principles can be traced to early work in [[psychology]], such as that of [[William James]].<ref>{{cite book |last1=Anderson  |first1= James A.|last2=Rosenfeld |first2= Edward |date= 1989|title= Neurocomputing: Foundations of Research|publisher= A Bradford Book |page= 1|chapter = Chapter 1: (1890) William James ''Psychology (Brief Course)'' |isbn=978-0-262-51048-6 }}</ref> Psychological theories based on knowledge about the human brain were fashionable in the late 19th century.  As early as 1869, the neurologist [[John Hughlings Jackson]] argued for multi-level, distributed systems. Following from this lead, [[Herbert Spencer]]'s ''Principles of Psychology'', 3rd edition (1872), and [[Sigmund Freud]]'s ''Project for a Scientific Psychology'' (composed 1895) propounded connectionist or proto-connectionist theories. These tended to be speculative theories. But by the early 20th century, [[Edward Thorndike]] was writing about [[human  learning]] that posited a connectionist type network.<ref>[[Edward Thorndike]] (1931) [http://hdl.handle.net/2027/mdp.39015010306069 ''Human Learning''], page 122</ref>

Hopfield networks had precursors in the [[Ising model]] due to [[Wilhelm Lenz]] (1920) and [[Ernst Ising]] (1925), though the Ising model conceived by them did not involve time. [[Monte Carlo method|Monte Carlo]] simulations of Ising model required the advent of computers in the 1950s.<ref name="brush67">{{cite journal |last1=Brush |first1=Stephen G. |year=1967 |title=History of the Lenz-Ising Model |journal=Reviews of Modern Physics |volume=39 |issue=4 |pages=883–893 |bibcode=1967RvMP...39..883B |doi=10.1103/RevModPhys.39.883}}</ref>