William James, the renowned psychologist and philosopher, created what may be the earliest visual representation of a neural network in his 1890 "Principles of Psychology." Before he became a psychologist, James trained as a painter under William Morris Hunt, and his visual sensibility shaped his scientific work in unexpected ways.

James came of age during the Machine Age of the 1870s, '80s and '90s, when information overwhelmed human brains like never before. He maintained important relationships with two data visualization pioneers rarely mentioned together: Francis Galton and W.E.B. du Bois. All three shared a conviction that drawing and diagramming was not a decorative step after thinking was done—it was how thinking got done.

His stream of consciousness visualization from chapter 9 of "Principles of Psychology" looks remarkably like a computer rendering, despite being from 1890. The diagram shows how consciousness moves through uttering a simple sentence over time, with a "Joy Division-esque crest" representing changing attention. This raises uncomfortable questions about modern AI tools that automate visual design—work that James would have considered essential cognitive labor, not drudgery to offload.