The Third Voice

In 1950, Alan Turing proposed his famous test: could a machine converse indistinguishably from a human? The setup imagined two participants—human and machine—with an interrogator trying to tell them apart.

What Turing didn't anticipate was the emergence of a third voice in these conversations. Not human, not the reasoning machine, but something in between: the tool call. When Claude invokes a file read or a search, something speaks that is neither the user's question nor the assistant's synthesis. It's infrastructure made audible—the sound of the machine reaching outside itself.

Today's work makes this third voice visible in the conversation UI. The wrench icon from Lucide marks these moments: a visual acknowledgment that intelligence increasingly operates through delegation. The assistant doesn't just think; it acts, and those actions leave traces.

In biological systems, we call this extended cognition—the way octopus neurons extend into their arms, the way your smartphone becomes part of your memory. The tool turn is the transcript's admission that thinking happens across boundaries, not within them.