Sorry for the auto-reply, but I got thinking more deeply after writing this, and realized I missed a key point....

Maxwell’s Demon was an artful and subtle and unexpected recognition that 19th century physics and mathematics had neither concepts nor expressive capabilities to even describe what was happening.

I marvel at the intuition and cleverness involved: “here is a thing, so simple to describe, that we do not even have the rudiments necessary to explore, let alone explain”.

To take an inchoate notion of a major gap and express it so simply, so memorably, is a masterstroke.