The Totally Blind Zombie Homunculus Room

From: Colin Geoffrey Hales <>
Date: Mon, 27 Nov 2006 17:20:19 +1100 (EST)

This discussion is a hybrid of a number of very famous thought
experiments. Unlike those thought experiments, however, this experiment is
aimed purely and only at scientists. The intent is to demonstrate clearly
and definitively the nature of subjective experience (phenomenal
consciousness) and its primal role in a scientist's ability to function as
a scientist.

Imagine a room. Its walls and celing and floor are matt black. There are
no doors or windows. All over the walls are digital displays which
announce numbers in warm, friendly colours. Up against all four walls and
up to international standard control desk height (roughly 750mm) is a
sloping console. Covering the console around all four walls are
pushbuttons. The number of displays is equal to the number of sensory
nerves entering a typical human brain from the peripheral nervous systems
including all sensory input. The number of pushbuttons is equal to the
entire set of effector nerves emanating from a typical brain. This total
number of displays and pushbuttons is in the millions.

There is a comfortable chair upon which is seated the room's sole
occupant, Marvin the human. Marvin is normal except for never having been
outside the room and having never otherwise acquired any knowledge of
anything other than that of the room and its contents. He knows absolutely
nothing of any sort of external world or any other people. He has no clue
about the external world except for what he can surmise from the displays
and buttons.

Marvin, like all healthy humans, has an experiential life which is the
collection of private phenomenal scenes delivered by his brain material.
These are operating normally except that Marvin has been deprived of all
the phenomenal content (experiences) that he ever could have received had
he been allowed outside the room. He has had a lifetime of experiences,
but all of them have been confined to depicting the room.

Marvin is a scientist. He studies the science of not-room. His life
consists of experiments which involve the pressing of buttons and the
recording of patterns in the displays. Over time an enormous volume of
data begins to show patterns for which Marvin constructs models. The
models are generalisations of the behaviour of the displays after buttons
are pushed in a certain way. He tests and refines the models and has
developed a form of symbolic representation of the behaviour of the
displays. Certain features on the display occur regularly enough that
names have been given to notional not-room phenomena. One is called the
tronelec. The mathematics of not-room includes a lot of rules about the
behaviour of tronelecs. In time Marvin realises that his exploration of
not-room can be done according to routine rules and he sets about a
systematic, exhaustive assay of the entire range of possible
button/display relationships.

Everything is going nicely but then one day a well known pattern does not
occur the way it used to. After a while the old pattern resumes. The whole
mathematics of not-room is undermined. It takes a long time for Marvin to
construct a new model that accounts for the novel behaviour. A new entity
called gytravi is needed. Then things settle down and routine systematic
exploration resumes.

In time a massive collection of not-room entities and behavioural rules is
constructed and begins to repeat itself. So much so that Marvin, after
checking and rechecking, finds that the model seems to have stabilised.

At this point we stop to survey the situation.

The first thing to note is that the room is an empirically verified
physiologically accurate representation of the sensory circumstances of a
human brain. Nervous activity effect/affect is replicated by
buttons/displays and all signals are standardised. There are no
experiential qualities (perceptual sensation qualities) associated with
this nervous activity. This is a physiologically verified, well
established empirical fact. Indeed the room is a little too kind - If you
discarded all the buttons and displays, then that is a more
physiologically accurate circumstance .

The main point is that this collection of totally sensationless signals is
exactly what is available to a human brain and through which all sense
measurement arrives. Consider the room without a Marvin in it. Based on
what evidence is there any reason to even conceptualise the existence of
an external world? Nothing in that room gives any indication of it. There
is no a-priori knowledge of not-room. No possible way to interpret any of
the signals. All there is is correlated behaviour - the behaviour of
displays correlated with other displays and buttons, none of which have
any other discernable impact. The room is quintessentially a zombie in the
sense it has no experiential life at all despite being wired as
extravagently as a complete human.

Marvin thinks of himself as a scientist. Exactly what is he a scientist
of? His science is, he thinks, the science of 'not-room'. But is it? All
he has is a very sophisticated model of display/button correlations. His
science is not about 'not-room' at all! His science is the science of room
display/buttons. He has absolutely no justification to any claim about
anything going on anywhere else, although that is how Marvin thinks of it.
His science is very very predictive of button/display behaviour. As to the
reality of the model he has developed? He has no way of contextualising
any of the abstractions he has created with the actual state of affairs in

Absolutely anything could be out there driving the displays and Marvin
will never know. Indeed worse than that, there may be an infinite number
of different ways that not-room could present the same display values and
Marvin would never know. The display data is fundamentally, intrinsically
ambiguous. Even if the displays and buttons were nicely grouped and
labeled all that would happen is that there would be expectations of
related behaviours in a group, which Marvin does not have to name himself.
It could even be named 'sight', 'sound' and so on and Marvin may
understand what that might mean, but it delivers no claim to any
definitive or unambiguous knowledge of not-room.

And that, fundamentally, is the real nub of the matter.

What is outside the room? It doesn't really matter. It could be an
elaborate multistory building with a ratsnest of electrical
interconnections done with a computer. It could be a control room in the
head of a giant robot. It could be literally wired up to a human body with
no brain. It could be a spaceship. None of that matters except in the
details. Marvin can never know because he has no experience available to
even imagine it.

To finish off the room scenario we now take Marvin out of the room. In his
place we leave a machine that is based on his systematic scientific
behaviour. It runs with clockwork and pneumatics from punched cards. None
of the displays are needed, none of the buttons are needed - they are all
directly connected to the new machine. The massively complex model marvin
has constructed, which has nothing whatever to do with 'not-room' except
in the most indirect of abstracted ways, goes on being verified and
occasionally amended using more rules for amending the model, also devised
by Marvin. The model can never say anything about any changes in
'not-room'. All it can sense is novel (unexpected according to the model)
behaviour in the sensing displays, which is an entirely different thing.

The main message to take from this is that this bizarre concoction is the
necessary circumstance that would exist in a human if it weren't for what
phenomenal consciousness provides a human scientist.

 You received this message because you are subscribed to the Google Groups "Everything List" group.
To post to this group, send email to
To unsubscribe from this group, send email to
For more options, visit this group at
Received on Mon Nov 27 2006 - 01:21:05 PST

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:12 PST