108
7 Materialism: The Brain As Computer
evidence reveals nothing more than neurons firing in the brain. All else is
figment.
An alternative to the identity theory is an approach known as functionalism.
The idea is that any complex system, of any kind, consists of many parts,
each of which carries out a specific task. In the animal body, for instance, the
heart pumps blood, the liver produces enzymes for breaking down complex
molecules, the kidneys filter impurities, and so on. Systems such as the animal body can be represented by flowcharts which exhibit all the components,
along with the task each component is mandated to carry out. Hypothetically,
every organ might be replaced by a machine which does the same job. If the
exact organization of the flowchart is retained then the resulting system would
function like a body.
The brain too consists of a great many modules, each dedicated to an
assigned task, such as memory, attentional focus, arousal and others. According
to functionalism, mental activity consists of a great many isolable functions.
We remember, weigh choices, make decisions, and so on. The way these activities interact may be represented in a flowchart. Moreover, it is plausible that
each of these fundamental activities could be carried out separately on a silicon wafer—and so long as we retain the same flowchart, the same processes
will unfold. It is irrelevant how the individual tasks are done: The essence of
functionalism is that all that matters is the way the tasks interact globally as a
system. Once appropriately organized, a system is what it is.
Functionalism, as well as the identity theory, are physicalist approaches to the
mind. What they have in common is that both argue that physical mechanisms
perform mental functions such as thinking and feeling. Both have a feature
called multiple realizability: It claims that elementary mental processes do not
need to be carried out on living organisms, but could be executed on artificial
systems so long as the same functional organization is retained.
There are other arguments, too, constructed in order to support the claim
that mind is merely the electro-chemical activity of the brain. Each one of those
arguments, however, leaves out the matter of sensation and felt experience.
They would be rock-solid scientific explanations if humans and animals felt
no pain, joy, sadness, and were not aware of what’s happening around them. In
fact, some of the best minds in cognitive science have found arguments which
purport to prove that sensation and awareness don’t really exist at all—and have
managed to convince themselves of this. In this way of thinking, sensations
and feelings are epiphenomena, that is, they are illusions, and don’t exist in the
world.
There are volumes devoted to arguments supporting as well as demolishing
the ideas of physicalism, but most of them are too technical to be discussed in
7 Materialism: The Brain As Computer
evidence reveals nothing more than neurons firing in the brain. All else is
figment.
An alternative to the identity theory is an approach known as functionalism.
The idea is that any complex system, of any kind, consists of many parts,
each of which carries out a specific task. In the animal body, for instance, the
heart pumps blood, the liver produces enzymes for breaking down complex
molecules, the kidneys filter impurities, and so on. Systems such as the animal body can be represented by flowcharts which exhibit all the components,
along with the task each component is mandated to carry out. Hypothetically,
every organ might be replaced by a machine which does the same job. If the
exact organization of the flowchart is retained then the resulting system would
function like a body.
The brain too consists of a great many modules, each dedicated to an
assigned task, such as memory, attentional focus, arousal and others. According
to functionalism, mental activity consists of a great many isolable functions.
We remember, weigh choices, make decisions, and so on. The way these activities interact may be represented in a flowchart. Moreover, it is plausible that
each of these fundamental activities could be carried out separately on a silicon wafer—and so long as we retain the same flowchart, the same processes
will unfold. It is irrelevant how the individual tasks are done: The essence of
functionalism is that all that matters is the way the tasks interact globally as a
system. Once appropriately organized, a system is what it is.
Functionalism, as well as the identity theory, are physicalist approaches to the
mind. What they have in common is that both argue that physical mechanisms
perform mental functions such as thinking and feeling. Both have a feature
called multiple realizability: It claims that elementary mental processes do not
need to be carried out on living organisms, but could be executed on artificial
systems so long as the same functional organization is retained.
There are other arguments, too, constructed in order to support the claim
that mind is merely the electro-chemical activity of the brain. Each one of those
arguments, however, leaves out the matter of sensation and felt experience.
They would be rock-solid scientific explanations if humans and animals felt
no pain, joy, sadness, and were not aware of what’s happening around them. In
fact, some of the best minds in cognitive science have found arguments which
purport to prove that sensation and awareness don’t really exist at all—and have
managed to convince themselves of this. In this way of thinking, sensations
and feelings are epiphenomena, that is, they are illusions, and don’t exist in the
world.
There are volumes devoted to arguments supporting as well as demolishing
the ideas of physicalism, but most of them are too technical to be discussed in