The Evolution of Language: Speech to Code

We talk about “language” as if it were one thing. It is closer to a stack of inventions, each built on the last, each storing thought a little further outside the body. Laid out in order, the sequence has a direction, and the direction is the reason I wrote Building Your First Brain.

This essay is the historical backbone for a set of pieces on how AI is changing human language.

Stage one: sound

The first shared signal was speech. Sound let one mind move a thought into another mind in real time. It was revolutionary and it was also fragile: the moment a sentence was spoken, it was gone, surviving only in memory. For most of human history, everything a culture knew had to fit inside living heads and be refreshed by retelling.

Speech made coordination possible. It did not make it durable.

Stage two: symbols

Then came marks that held meaning still. A notch, a tally, a drawn figure: the first symbols let a thought outlast the moment it was expressed. This is the quiet hinge of human history. Once meaning could sit on a surface, it stopped depending on memory alone.

Symbols were limited, often standing for specific things rather than the full flexibility of speech. But the principle was set: thought could be externalised.

Stage three: writing

Writing generalised the symbol into a system that could capture anything speech could. This is the stage that changed the mind itself. When thought can be stored, it can also be revised, compared, and examined. You can hold an argument still long enough to find the flaw in it.

The downstream effects are almost the whole of recorded civilisation: law, scripture, science, the contract, the ledger. Cognitive historians make a strong case that literacy reshaped attention and reasoning, not just record-keeping. Writing did not only store thought. It taught thought new tricks.

Stage four: code

The most recent completed stage is language a machine can run. Code is the point where symbols stop merely describing the world and start acting on it. A written instruction now does something, at scale, without a human in the loop.

Code is also what made the current moment possible. The language models reshaping how we write are themselves built and trained in code. We used the fourth stage of language to build machines that now operate on the first three.

The pattern, and the fifth stage

Step back and the trend is unmistakable. Each stage:

• stores meaning further outside the body,
• makes it more durable and more shareable,
• and reshapes the minds that use it.

Sound lived in the moment. Symbols lived on surfaces. Writing lived in systems. Code lives in machines. Each step externalised more, and each step changed us.

Follow the line and it points somewhere specific: a stage where communication skips the external symbol entirely and moves intention more directly between minds and machines. That is not a prophecy. It is an extrapolation, and it is precisely what brain-computer interface research is, very early and very imperfectly, trying to build.

Why the direction matters

The reason to care about the pattern is that we are, for the first time, living through two stages at once. Code is mature. The fifth stage is being prototyped. And large language models sit in between, industrialising the production of stages one through three.

When the layers of a stack all move together, the stack does not stay the same. Working out what that means for meaning, identity, and the texture of being human is the project of Building Your First Brain, which is free for the first 1,000 readers.

Further reading

• For the deep history of how marks became writing, the scholarship on early scripts collected by institutions like the British Museum is a careful starting point.
• The transformer paper marks where stage four began operating on stages one through three at scale.