need to be synthesized, to the extent that it has an ancestry rather than a manufacturer, to the extent that it does reproduce itself independently of us, to the extent that it is no longer an artefact but is self-moving and self-reproducing and lives a life of its own. And this, I think, shows that we were right to contrast being alive and being assembled by others. Even if we did assemble such a machine in the first place, we could regard its successors as alive just in so far as they no longer