Traces of the old medium that persist (residues) until the cognitive ecology no longer sustains them, at which point they collapse into irretrievable ruins.
Every media transition leaves behind two kinds of artifacts. Residues are traces of the old medium that continue to function within the new—diminished, transformed, but epistemically productive. Proverbs are residues of oral wisdom in literate culture. Handwritten notes are residues of manuscript intimacy in print culture. Ruins are capacities that have collapsed entirely, leaving only evidence of their former existence. The Homeric bard's fifteen-thousand-line memory is a ruin; no literate person sustains it, because the cognitive ecology (a world without external storage) that made it necessary and possible no longer exists. Ong's distinction matters because residues can be preserved—documented, taught, maintained through deliberate practice—while ruins cannot. Once the cognitive world that sustained a capability has been replaced, the capability becomes archaeologically interesting but functionally irretrievable. The AI transition is producing both: residues of literate consciousness that may persist for a generation or two, and ruins forming now in real time.
Residues and Ruins
In The You On AI Field Guide
Ong developed this framework by studying what happened to oral cognitive capabilities