It is one of the fundamental lessons of broad literary reading and of historical study that the human mind has been much the same over time and geography. Careful reflection on what we can discern of the mind of an ancient author, and allowing for the projection we inevitably make of our own mind into that of another, there are broad similarities. Indeed, the reality of projection, which I am so far from denying that I emphasize it, is indeed a proof this suggestion. The fact is that we are able to project ourselves into the writings of even a distant period without much torsion or neglect of the kind that we must enter into when, for example, creating cartoon narratives of talking animals or vegetables or vehicles. That is in itself rather remarkable. If the human mind had changed very significantly it would simply not be true.

Indeed, it seems possible to me that the brain may have an approximate maximum level of informational complexity, consisting of the evolved structure and the information it acquires, and that this accounts for our intuition that there has been little or no change in the mind over history, or indeed between pre-technological (and pre-literate) peoples and our own time. We certainly represent the world in different ways, and as a consequence are much more successful at manipulating the world, for these mental representations are much more accurate and adequate to our purposes, and in that sense they certainly can be termed more complex.

But the difference in the brain itself is, all told, not that great, and most of the variation in complexity that we observe is accounted for in the representations and other structures external to the mind, and the greatest barrier to understanding a person in distant period is the lack of such clutter.