Can Men Think About Thinking Machines?

Writers are polarized between those who firmly believe that a machine can never think, no matter what the definitions of "machine" and "think," and those who have been more willing to lay down criteria, in many cases trivial, such that if a machine passes the criteria, it can be said to think. The arguments are so polarized that it has become an either/or situation, reminiscent of one of science's earlier and famous either/or arguments, that of mechanism versus vitalism in explaining the nature of life. Indeed I would say that the twentieth century's counterpart to the nineteenth century's debate over mechanism and vitalism is the question of whether machines can think.

To indicate how wide the rift is, I have chosen a few excerpts. The first is from an article entitled "The Machine That Is Man" by B.F. Skinner, perhaps the leading exponent of behavioristic psychology today.

"Man is a machine, but he is a very complex one. At present he is far beyond the powers of men to construct – except, of course, in the usual biological way. Only those who believe that something nonphysical is essential to his functioning are likely to question this. If a science of human behavior is impossible because man possesses free will, or if behavior cannot be explained without invoking a miracle-working mind, then indeed man cannot be simulated. This is, of course, often argued. One scientist has insisted that "the brain is no more than a physical mechanism which, without the mind, is not unlike the so-called 'electronic brain' of industry. But without the guiding mind, the brain comes to little." If we believe with Vannevar Bush that "science is not enough" and that consciousness and free will have not been scientifically analyzed, then we may doubt that man is a machine or that any machine can simulate man. But as our understanding of human behavior increases we appeal less and less to explanatory fictions and we can then accept the fact that the essential differences between machines and men concern componentry. The problem of simulation is the technical problem of working with the stuff of which the human body is made. A machine that simulated human behavior in detail would indeed tell us the Inside Story. We should have only to look at the blueprints to see what entered into the creation of man. Like the Inside Story of physiology, however, it would tell us nothing new about behavior. Only when we know what a man actually does can we adequately simulate his behavior. The Outside Story must be told first."

The second excerpt is from the philosopher Michael Scriven's well-known essay, "The Mechanical Concept of Mind."

"Consciousness is not a property which can be detected in a machine by any physical examination, because it cannot be identified with any physical characteristics of a machine… The fundamental element… is the subjective impression and it is exactly this element whose presence in the robot is in question."

Or, as an example, consider the following by Paul Ziff:

"Ex hypothesis robots are mechanisms not organisms, not living creatures. There could be a broken down robot but not a dead one. Only living creatures can literally have feelings."

It is also important to realize that the debate goes much deeper than general statements of philosophical attitude. Both sides can mount an impressive array of scientific work to support their positions. In fact, it is precisely because both sides can support their arguments with evidence that it becomes important to analyze the differences. Why do two groups reach such different conclusions when they start from much the same evidence?

Excerpted from Can Men Think About Thinking Machines?, an essay by Ian I. Mitroff, which appeared in the journal ETC. (Vol. 27, No. 4), published by the International Society for General Semantics, December 1970. At the time of publication, Mitroff was a Professor at the Graduate School of Business, University of Pittsburgh.