🚀 go-pugleaf

I would like to make a few point that seem clear to me, but apparently
aren't clear to others in this discussion.

1) All physical objects are not machines. For example, stones, clouds,
flowers, butterflies, and people are not machines. This should be
obvious, but some people use the word machine to include all physical
objects. Not only is this contrary to ordinary usage, it obscures an
important distinction between what is an artifact and what is not.

2) Not all machines are computers. Lamps, screwdrivers, and cars are not
computers.

3) There are some activities which can be performed by physical objects
and machines which cannot be peformed by computers.  Birds can fly and
airplanes can fly, but computers cannot fly.  Of course, a computer can
control an airplane, but this misses the distinction I am trying to
make.  The distinction is that all computers, as computers, are
equivalent to Turing machines.  If the computers performs some other
activity during its operation than executing a program (for example,
flying) it is because the machine which contains the computer is 
capable of the activity (as airplanes are capable of flying).

4) The simulation of a physical activity by a computer cannot be
identified with the physical activity. A computer running a flight
simulation program is not flying.

5) Hence, while it may be possible to build a machine that thinks, it
does not follow that it will be possible to build a computer that
thinks, as not all physical activities can be performed by computers.

6) While there are good reasons to believe that thinking is a physical
activity, there are no good reasons for believing that thinking is the
execution of a computer program. Nothing revealed either through
introspection or the examination of the anatomy of the brain leads to
the conclusion that the brain is operating as a computer. If someone
claims that it is, the burden of proof is on that person to justify that
claim. Such proof must be base on analysis of the brain's structure and
not on logical, mathematical, or philosophical grounds. Since even the
physical basis of memory is poorly understood at present, any claim that
the brain is a computer is at best an unproven hypothesis.


						Bernie Simon