I still don't know what it means to be in London.

The present encodes the past. London as a city of reused parts, of pieces accidentally left. But that bits of it are old isn't what defines it.

The cross marks in curbstones, indicators of which stonemason cut it, or of a parallel city. A turf war we can't understand, conducted between invisible forces with the power to engrave rock with their fingers.

London worn smooth, channels carved by flows of people.

Except it's not worn smooth. Not all over. I'd say London is constantly renewed, or in flux, or changing. But it's not. Not really.

It's not a city of contrasts. Ancient tradition doesn't sit next to futurist corporation. Skyscraper is shaped into something this fits, and ancient is internalised by the Now.

And it's wrong to talk of Londoners as a shoal or as ants. In each face, again, the present encodes the past. I see people I recognise around Hammersmith. Not because we share a routine, just they're around. People move in small circles.

But sometimes they don't.

People aren't especially different. They aren't especially the same. London isn't ancient, or modern, or even a contrast of the two. It isn't bustling, isn't urban and unforgiving. It's not tangled. The tiny hidden Londons aren't nestled or hiding. They're just between things, waiting for people to look closer.

London's not a village. But it's not overwhelming with the mass of humanity. It's not a beehive, and it doesn't feel like it's an infinite expanse of little boxes full of people. It doesn't sprawl. London sits easy with itself.

When I cross the city, I'm not swimming through concrete and I'm not wading through an urban landscape. I'm not lost. But I am travelling, London does change from place to place.

This is all I can say about London:

There's no one thing that defines London. London is an ecology; forests, tundra, rolling hills with still lakes, rocky coasts with crashing waves. Jungles, deserts.

There is no average London. I can't say that every piece is joined to every other -- every piece is joined to some. It's irreducible. Self-sustaining. Eternal. A maximally complex meshwork, and that complexity includes both noisy and barren areas, meshed together across both space and time.

London has achieved the climax state.

And we walk this city. There's no way to make generalisations, except sometimes. There's no way to know how complex or simple a place will be, except sometimes. There's no way to extrapolate, except sometimes. You get to know London, and it gets to know you. Sort of.

London right Now is just London. The most perfect, most complex, the social Hebb-reflection of humanity's reality. The is-london. The archetype that other cities - including past and future Londons - are just slices of.

I'm off to Balham for the afternoon.