The human-machine boundary

First published in The Guardian, July 2016

In his 1963 book God and Golem, the founder of the cybernetics movement Norbert Wiener suggested a compelling thought experiment. Imagine cutting off someone’s hand, he wrote, but leaving intact the key muscles and nerves. Theoretically, a prosthesis could connect directly both to nerves and muscles, giving the subject control of the replacement organ as if it were real (I’m indebted to Thomas Rid for highlighting Wiener’s thought experiment in his new book, Rise of the Machines).

So far so sensible: this scenario was a reasonable extrapolation at the time, and is close to becoming a reality today. Wiener, however, went further. Having imagined an artificial hand able to replace its original, he wondered why we should not now imagine the addition of an entirely new kind of limb or sensory organ? “There is,” he wrote, “a prosthesis of parts which we do not have and which we never have had.” There was no need to stop at nature. Human-machine integration could in theory blur its boundaries well beyond replacement.


It’s 14 July 2016, and between typing this paragraph and the last I dashed outside with my iPhone to catch a Pokémon lurking next to a tree (a cute orange lizard: Charmander, weight 8.5kg, height 0.6m).

What would Wiener have made of this? I suspect he would have been delighted. While I’m playing Pokémon, my smartphone functions much like a sensory prosthesis. In order to move my avatar around a map, I must move myself. When I get close enough to a target, I hold the device up and through its camera see something superimposed on the world that would otherwise be invisible. It’s like having a sixth sense. My Pokémon-gathering escapades place me somewhere between a cyborg and a stamp collector.

Yet there are also elements in this species of enhancement that clash with Wiener’s vision. If I had a superhuman prosthetic eye able to see infrared – like Arnie’s beloved cybernetic organism in the Terminator movies – I could step outside into the dark with clear vision. I would have access to actuality in a fresh way: a machine-enhanced grasp of what’s under my nose. This is the kind of enhancement that technology has offered humans over millennia. We move faster, further; we enhance the strength of our limbs, the reach of our wills; we look deep into space, or at the microscopic order of things. We magnify our scope and capacities.

None of this is quite like playing Pokémon. What I see and do while lobbing tiny balls at a cartoon orange lizard does not exist outside of the machines I’m using. Yet nor is it a straightforward piece of mediation like reading a book or watching a movie. The experience is present on my screen, in my mind, and in the dance of data between mobile device, GPS satellites, mobile networks and distant servers. And everyone else with the right app is welcome to join in.


A clue to what’s going on lies in a term first coined in 1990: augmented reality. What’s on offer is a supplement rather than straightforward enhancement: an act of layering and addition. My smartphone is not helping me to see the world with superhuman acuity (quite the reverse: I nearly fell into a canal while capturing that Charmander). Rather, it’s like a third eye opening onto the information realm – a gaze overlooking the Earth’s oceans of data.

In a famous 1974 paper, the philosopher Thomas Nagel asked what it might feel like to be a bat. We cannot begin to discuss such a question, he argued, until we accept that the universe as experienced through a bat’s sensory organs is alien to our psychological reality. A bat’s primary sense is sonar. It may share a planet with us, but there is no bridge between our experiences.

What, I wonder, does it feel like to be an iPhone? I don’t mean to imply that machines have feelings. Rather, I’m intrigued by the fact that the inputs received by my smartphone – its experienced reality, if you like – are not tied to any particular location in the way my inputs are. Its world is the network. A query is issued, a matched response is served – the device is above and beyond actuality as I experience it. And yet we continuously, solicitously interact. As communications technologies have done since at least the age of the telegraph, I am subtly distributed by my connection to the connected tool: blurred between networked spaces.

We are barely at the beginning of this process, one characterised by the astonishing intimacy of our interactions with and through digital devices. Information is everywhere and nowhere. It is simultaneous, placeless. Similarly, augmentation trumps enhancement because it is unconstrained by the actual – because there is no limit to how far my experience of the world can be supplemented or supplanted. The free download of a single app turns physical space into a gameboard. Gleefully, my phone and I turn presence into play. In augmented reality, all the world’s a screen.


Today, Pokémon lives on my mobile device. Tomorrow – by which I mean within five years – it will make the magic leap to retinal projection, into something increasingly labelled “mixed reality”: the seamless interfacing of informational artefacts and environment.

As Wiener foretold half a century ago, the boundaries between human and machine experience are not so much interlacing as being erased. Is it a new sensory organ, this ever-more-intimate interface with information? Perhaps. It’s certainly a mental prosthesis whose absence already feels crippling. We are beginning our migration towards a networked sensorium. The question is no longer how technology makes us feel. It’s whether, without it, we are even ourselves.