Like many developments in the history of computing, some of the ideas for a GUI computer were thought of long before the technology was even available to build such a machine. One of the first people to express these ideas was Vannevar Bush. In the early 1930s he first wrote of a device he called the “Memex,” which he envisioned as looking like a desk with two touch screen graphical displays, a keyboard, and a scanner attached to it. It would allow the user to access all human knowledge using connections very similar to how hyperlinks work. At this point, the digital computer had not been invented, so there was no way for such a device to actually work, and Bush’s ideas were not widely read or discussed at that time. —Jeremy Reimer —A History of the GUI (Ars Technica)
Bush’s vision was tied to his vision of the potential of analog computing, so it’s a stretch to use the fact that digital computing hadn’t been invented to dismiss Bush’s ideas as unworkable. Wartime research discoveries had led to a boom in scientific publications, which gave his ideas from the previous decade more currency.