This essay is a response to John Searle’s article: http://users.ecs.soton.ac.uk/harnad/Papers/Py104/searle.prob.html

 

 

EXPANDING THE BOUNDARIES OF MATERIALISM:

THE PROBLEM OF CONSCIOUSNESS

In attempting to understand a phenomenon like consciousness from a materialist perspective without falling prey to a biological reductionism, it is instructive to look at the recent work by John Searle on this subject.  Searle bravely attempts to put a materialist stamp on the phenomenon of consciousness, to avoid a concept of mind, only to fall victim to scientistic fallacies. 

Searle argues correctly that consciousness is the outcome of a system. In this context, a system is something that produces an outcome, and an investigation into a system needs to determine the necessary components and the necessary relationships among those components to produce that outcome.  A system also has a set of boundaries.  Everything necessary to produce that outcome belongs inside those boundaries and what is not necessary is in the environment of that system but not inside. 

Searle claims that the system that produces consciousness consists only of a particular neurobiological process and is bounded by the brain.  The best counterargument is Searle’s own argument against the AI types who insist that technological developments will eventually yield a thinking computer.  Searle shows that no amount of technological sophistication will produce a mechanism capable of behaving like an organism because of the strictures of mechanical, closed, systems.  Here, however, he goes in the opposite direction and concludes that the brain is an organism, or at least a component of an organism, behaving like a closed mechanical system:

As far as we know anything about how the world works, variable rates of neuron firings in different neuronal architectures cause all the enormous variety of our conscious life. All the stimuli we receive from the external world are converted by the nervous system into one medium, namely, variable rates of neuron firings at synapses. And equally remarkably, these variable rates of neuron firings cause all of the colour and variety of our conscious life. The smell of the flower, the sound of the symphony, the thoughts of theorems in Euclidian geometry -- all are caused by lower level biological processes in the brain; and as far as we know, the crucial functional elements are neurons and synapses.

 

To say that stimuli come from the “external world” is to accept as QED a bifurcation that remains questionable.  Once you define something as “external,” you have defined the boundaries of a system.   Searle has accepted the epidermis as a finite boundary that defines what is external, when it may be only a convenient or phenomenal boundary within a larger system. 

Searle makes no distinction between perception and thoughts, equating the smell of the flower with thoughts of the theorems in Euclidean geometry.  To say that both are caused purely by the firings of neurons, Searle would have to argue that just as there are receptors for the chemicals of floral aromas, there are receptors for Euclidean formulations.  Searle would ultimately have to stipulate a Chomsky-like reductionism, an innate capability for Euclidean formulations within the human brain, as Chomsky stipulates an innate capacity for syntax.    It is a reductionist argument because innateness cannot be proven or disproved.  Stimulus and response is a communication mechanism that occurs within a complex system and between a system and its environment.  That system may involve neurons firing across synapses, but it does not follow that lower level brain processes cause the things they may be involved in making appreciable.  It is a treacherous business to assign causality solely within a closely bounded system, and Searle does so too easily.

For Searle, the key to avoiding a non-materialist explanation of consciousness is to insist that a system based on lower level components can produce higher level features:

More pointedly, does the claim that there is a causal relation between brain and consciousness commit us to a dualism of ‘physical’ things and ‘mental’ things? The answer is a definite no. Brain processes cause consciousness but the consciousness they cause is not some extra substance or entity. It is just a higher level feature of the whole system. The two crucial relationships between consciousness and the brain, then, can be summarized as follows: lower level neuronal processes in the brain cause consciousness and consciousness is simply a higher level feature of the system that is made up of the lower level neuronal elements.

While it is appropriate for Searle to be talking about a system, he does not address the problem of system boundaries.  He assumes that systems simply have higher level features without investigating the possibility that these higher level features arise from higher level boundaries and are simply perceived at a lower level as a particular phenomenon, such as the two dimensional creature in Abbott’s Flatland perceiving a point becoming an increasingly larger circle and then diminishing to a point again, which is really a three dimensional sphere moving through his plane.   The creature bounded by a two-dimensional system simply had no reference point from within that system to understand an object that was perfectly explainable from a higher bounded, three dimensional system that is capable of including the lower level two dimensional system.  Consciousness, which Searle claims is a higher level feature of a low-level system, may be perfectly explainable from a set of higher level boundaries.

To explain how a system comprised of lower level components can give rise to higher level features, he refers to the phenomenon of liquidity:

Lower level elements of a system can cause higher level features of that system, even though those features are features of a system made up of the lower level elements. Notice, for example, that just as one cannot reach into a glass of water and pick out a molecule and say ‘This one is wet'’ so, one cannot point to a single synapse or neuron in the brain and say ‘This one is thinking about my grandmother’. As far as we know anything about it, thoughts about grandmothers occur at a much higher level than that of the single neuron or synapse, just as liquidity occurs at a much higher level than that of single molecules.

 

Here, Searle is simply wrong.  Liquidity is not a higher level feature of a system that is bounded by molecules alone.  Rather, liquidity is a property of molecules moving at a certain speed.  If we can determine the speed of a molecule of H2O, we can determine whether that molecule has the property, liquidity.  Searle wants to reference systems, but seems to have little idea what a system is or what its characteristics are. 

Searle wants to say that liquidity is a feature of a system bounded by molecules.  No higher level component need be present to produce liquidity, simply an aggregate of lower level components.  But speed needs to be a property of those molecules if they are to achieve liquidity.  The problem is that speed can vary.  At a higher speed, those molecules will no longer be liquid but will be gas.  At a lower speed, the molecules will be solid.  Clearly, a particular speed is a necessary feature of water molecules to be classified as liquid.  Nothing inside the system bounded by molecules can produce that variability. Some event or stimulus from outside that boundary must be present.  Speed is a response to a stimulus, i.e., heat, which comes from beyond the boundary defined by molecules.  So liquidity is not a higher level feature of a system bounded by lower level components, i.e., molecules; it is a feature of a lower level component in a system whose boundaries extend beyond that component to include a source of heat.  And when you consider that heat is work, we must expand the boundaries yet again to include an agent that produces work.  Since liquidity is molecules moving at a particular speed or range of speeds, the boundary of that system will need to expand to include something capable of controlling work.  Once Searle introduces someone reaching into a glass of water and feeling wetness, the system will expand yet again to include a perceptor and whatever else needs to be added to understand the phenomenon of perception.

The boundaries of our system will eventually expand to include the entire universe, and we will be stuck in what we might call an augmentatio ad absurdum.  Whatever boundaries we assign to a system are provisional boundaries that we set to define a unit of analysis that allows us to understand a particular phenomenon, like wetness.  The boundary that Searle has set around this particular system, i.e., molecules, is too narrow for understanding the phenomenon of wetness.  A lower level component only has a higher level feature by participating in a higher level system.  The molecule in aggregate does not cause wetness as Searle insists.  Since it is impossible to have a molecule without speed, i.e., without a material state, the boundary that Searle wants to put around molecules is fictitious.

Searle has the same problem with neurons that he has with molecules.  Elsewhere, Searle has shown that computers will never think, i.e., that binary decisions, however multiplied, will never produce thinking.  Now, however, we are told that the firings of neurons, exponentially multiplied, will produce consciousness.  But the neurons will not produce consciousness any more than the molecule will produce wetness or binary decisions will produce thinking.  Consciousness will be a feature of those neurons as those neurons play a role in whatever higher level system is implicated in the production of consciousness, whatever those boundaries may be. 

Searle is quite certain that brain processes, and brain processes alone, produce consciousness.

I want to argue that we simply know as a matter of fact that brain processes cause conscious states. We don't know the details about how it works and it may well be a long time before we understand the details involved. Furthermore, it seems to me an understanding of how exactly brain processes cause conscious states may require a revolution in neurobiology.

This is a treacherous statement.  An eighteenth century scientist could easily have said that we know as a matter of fact that phlogiston causes fire but that it would take a revolution in our understanding of chemistry to know how it causes fire. 

Searle wants the boundary of that system that produces consciousness to be, at most, the brain.  But even in purely physiological terms, that boundary is unlikely.  The body is best understood as communities of cells in communication with each other.  The endocrine system is the communication system, sending chemically coded messages among these communities of cells, telling them what to do next and how to cooperate with other communities of cells.  Searle seems uninterested in the question of why neurons fire or in the biology of that process; that they do is sufficient for him. The firing of neurons, however is a response to the messages coming in to the brain via the endocrine system from other communities of cells.  So consciousness is at least a function of the entire body if not the function of a higher level system whose boundaries may extend beyond the body itself.  But the real question is whether that boundary extends beyond the epidermis.  Searle is trying to take Cartesian reductionism one step lower in discovering the irreducible.  If Descartes says, “I think, therefore I am,” then Searle is saying, “Neurons fire, therefore, I think.”

It is likely that consciousness occurs at the species level but we experience it at the individual level because we have self-consciousness but not species-consciousness.  Just as the denizen of Flatland understands the sphere as a special kind of two dimensional experience because he cannot comprehend a third dimension, Searle asserts that consciousness is a special kind of individual experience.  When he asserts that “we simply know as a matter of fact that brain processes cause conscious states,” he is merely insisting on an individual cause for what he experiences as an individual phenomenon but which could be something else.  But the fallacies he runs into while attempting this explanation and his constant assertion that we don’t know yet how this happens suggest that he’s missing something important. 

The primacy of language in the experience of consciousness suggests a cause beyond the individual level.  Any thought beyond the level of elemental drives or emotional states is going to require a symbolic language to contain and express.  Language being a tool of and an emanation from human association means that human association is the necessary condition for the level of consciousness that enables abstract thought.  The flaw in the Cartesian formulation is the a priori assumption that thinking is an entirely individual experience.  Only under that assumption can thinking precede being as Descartes asserts.  Searle is simply expressing his faith in the Cartesian formulation, cogito ergo sum.  Since the self is the basic unit of bourgeois social organization, Descartes was building the foundation for the bourgeois intellectual superstructure.