Could a computer ever have a mind?

Yes, a computer could have one, said Alan Turing in 1950, when he devised his famous Turing Test. He wanted a behavioral test for the presence of mind that would not prejudice the outcome by considerations about whether the thing possessing the mind has a human shape or a human voice or human biology. Turing wanted to avoid having to define mind itself, but thought that his test, which is a test for language understanding, is so difficult to pass that if a computer program did pass it, then everyone would agree that it really understands language and so has a mind.

The Turing Test has many versions. Here is one. It involves a contest in which the contestant is placed in a temporarily sealed room. The contestant is either a computer or else human who understands Chinese, though which one is initially unknown to the judge of the contest. The room serves as a black box except that the room is connected via the Internet to the judge whose job it is to ask written questions of the inhabitant of the room and then on the basis of the answers guess whether the room contains a computer. The judge is required to send messages electronically into the room that are written in Chinese. The contestant will send back written responses. The judge who does understand Chinese can get outside assistance from experts.

The test is passed by the computer if during a long series of trials the judge cannot correctly identify the computer at least 70% of the time. Turing’s idea is that passing the test is a sufficient condition for understanding Chinese, though not a necessary condition, provided the judge does his or her best. The computer will have to give false answers to questions such as the Chinese version of, “Are you a computer?” and “How would you describe your childhood?” and “Do you know the cube root of 10⁴³- 3?”

This Turing Test is considered an excellent test not only by behaviorists but also by philosophers of mind who favor functionalism. This is because functionalists believe having a mind consists merely in having one’s parts function properly, regardless of whether those parts are made of flesh or computer chips. According to functionalism, understanding language can consist only in having the ability to manipulate symbols properly. This idea that physical constitution is unimportant is called “multiple realizability” in the technical literature. Functionalism with its endorsement of multiple realizability is the most popular philosophy of mind among analytic philosophers.

John Searle, a philosopher of mind currently at U.C. Berkeley, has offered a Chinese Room Argument that I consider to be an effective refutation of functionalism because it serves as a refutation of the idea that language understanding can consist solely of symbol manipulation by a computer. Suppose, says Searle, that we had a computer program that can pass the Turing Test in Chinese. Then the functionalist must say the machine truly understands Chinese and so has a mind. But, says Searle, although he himself understands no Chinese, he could in principle step into the room of the Turing Test, replace the computer that passed the test, follow the steps of the computer program as they are described in English and do anything the computer program does when it processes Chinese symbols. Written Chinese symbols sent into the room by the judges would be processed more slowly by him than by the computer, but speed isn’t crucial for the test, and there could be a redesigned test that controls for speed of answering. In short, you don’t need to understand Chinese in order to pass the Turing Test in Chinese. So, functionalism is incorrect.

No, responds Daniel Dennett who is a well-known philosopher of mind and defender of functionalism. Searle is fooling himself. He may not consciously realize that he himself understands Chinese, but unconsciously he shows that he does. If the room passes the Turing Test for Chinese with Searle sitting inside doing the work of the computer program, then the room as a whole system understands Chinese even its Searle-part says it doesn’t. Similarly we readers of this blog understand English even if our liver knows no English. This response by Dennett is called the Systems Reply to the Chinese Room Argument. It is the favorite response of the functionalist to Searle’s attack on functionalism.

To speak for Searle here, I believe the Systems Reply fails to save functionalism. I am not claiming that a machine couldn’t pass the Turing Test. A cyborg might pass. I know for sure that a machine can pass the test. I myself am a physical machine; but the philosophically key point is that I do not understand language just because I am an effective symbol processor. Mere symbol processors can’t know what they are doing. I understand language because I am an effective symbol processor with a flesh and blood constitution. Biochemistry is crucial for understanding language, even for understanding that a certain pattern on a computer screen is a meaningful Chinese symbol. Almost all neurobiology researchers appreciate this and thus pay close attention to biochemistry as they make their slow advance toward learning the details of how the brain causes the mind. Functionalists do not appreciate this.

Yet every example we have of an entity that understands language is made of flesh and blood, of meat. (Yes, I am a “meat chauvinist.”) I don’t say I know for sure that meat is required for understanding language, nor how to solve the mystery about meat that enables it to realize a mind (surely not every feature of the meat is essential), but I believe there is enough evidence to say we do know that meat, or at least something with a meat-equivalent-biochemistry, is needed; and we know that any neuroscience researcher who ignores this fact about biology is not going to make a breakthrough. Yet, Dennett and the other functionalists are committed to the claim that they know meat is not required. That’s their big mistake.

Brad Dowden
Department of Philosophy
Sacramento State

We may believe the red rose is red

In my History of Early Modern Philosophy, I tell the story of how the cutting-edge metaphysics of 400 years ago became the common sense of today.

Two pieces of common sense:

1. We may believe that the rose is red, but this belief is strictly and literally false.
2. Strictly and literally, nothing really is red.

These express the view of colors propounded (in different versions) by Galileo, Descartes, and Locke.

It seems only fair to confront common sense with the metaphysics of today.

Antirealism about ‘secondary qualities’ derives its plausibility from early modern accounts of mental content. We acquire our concept of red from the contents of our perceptual experiences: ‘adventitious ideas’ (Descartes), ‘ideas of sensation’ (Locke). From these arise thoughts of red, as well as the meaning of ‘red.’ Both the sensory and the cognitive content are thus subjective, logically private, and transparent to the subject, who is infallible about them.

What happens when we combine the commonsense view of red with current views on mental content and concept formation? (And add in the arguments of philosophers like Barry Stroud, Jonathan Ellis, and John Campbell.)

We clearly run afoul of the Private Language Argument. A meaning, a concept, must follow a rule. But ‘purely private rule’ is an incoherent notion. As Wittgenstein said: “…(W)hatever is going to seem to me to be right is right. And that only means that here we cannot talk about ‘right’.”

We also get into trouble with Twin Earth-style arguments, from which Putnam concludes, “Meanings ain’t in the head!” They are not subjective, nor are we infallible about them.

It conflicts with externalist and representationalist accounts of mental content according to which we have no conscious access to our ‘ideas.’ Gilbert Harman asks, “Does your experience represent this redness by being itself red at a relevant place, in the way a painting of a ripe tomato might represent the redness of the tomato with some red paint the appropriate place on the canvas?” Harman concludes that there is no ‘mental paint.’ Our perception and thought represent the world as being a certain way.

Consequently, when we see something as red, this seeing must be a connection to the external world. What is its object? Some property of the rose, evidently: a structural property of the surface by which it absorbs certain wavelengths, or the dispositional property to do that. Or a dispositional property to represent an object thus and so. Or a simple, transparent property supervening (somehow) on physical properties.

Surely the natural candidate for being the referent of our concept red is that property.

But then our belief that the rose is red is true, not false.

Some things really are red.

The remaining issue, then, is what kind of property being red is. If it’s a structural property of surfaces, or even a dispositional property based upon its physical structure, then arguably colors are physical.

This would fit with the early modern denial of colors as having no function in scientific explanations. If they’re physical, they would.

But this moves a bit too fast. Colors function in explanations not because of purely physical interactions with the visual systems of animals, but in virtue of how they represent things. Color explains things not in terms of structural properties but in terms of how objects appear.

This would make color a real property of objects, but not a physical one.

Thomas Pyne

Department of Philosophy

Sacramento State

Good-bye to Libertarianism

I find the hardest part of a political philosophy course to teach is the section on libertarianism because I can’t take it seriously. It is a philosophy for the 19th century age of the robber barons and 21st century Silicon Valley billionaires who want a gloss of theoretical respectability to cover their vast wealth. But for the rest of us it has nothing to offer.

One central pillar of their theory is that property rights are natural rights, but they have been completely unsuccessful at making a plausible case for such a claim. Locke’s attempt has been subject to withering criticism and Nozick doesn’t even try to prove there is a natural right to property, he just assumes it is a fact. Much of their case for a minimal state whose functions are limited to enforcing the criminal law, torts, property and contract rights rests on the assumption that property ownership is a natural right and therefore any taxation for purposes other than maintaining the minimal state are invalid without the individual consent of the property owner. Hence, any state regulation of private enterprises is unacceptable. This puts us back in the Lochner Era of a century ago when the courts agreed that state efforts to impose health and safety regulations for workers violated the rights of the property’s owners, as did labor unions (collective bargaining) and minimum wage laws. Nor could libertarians support, consistent with their theory, a progressive income tax or a tax on stock sales (like the Tobin Tax) and other forms of capital because they would violate property rights. Moreover, curbing extreme inequality of wealth is not part of their conception of justice.

As for the second pillar of their theory – the natural right to liberty – it is loosely understood as the absence of coercion, deceit, fraud, extortion and other sorts of deliberate effort to control the behavior of others, i.e., negative liberty. Libertarians appear to hold that a society with extensive negative liberty is all a person needs from the state to be self-determining. People are entitled to only as much self-determination as they can attain within the institutional framework of an unregulated free-market. But liberals look at it differently. They draw a distinction between the allocative function of markets and their distributive function. 

Liberals like me agree that market systems – when properly regulated – can do an effective job of producing goods and services efficiently; their allocative function. But they often fail quite dramatically at distributing income and wealth – the rewards of work – in a just manner. Markets distribute incomes in response to supply and demand. Wages and salaries fluctuate in response to the relative supply of workers and demand for the product or service produced, factors that are largely independent of the worker’s merits. Nor, as the historical record shows, does a market economy always guarantee employment for all who want it. So to ensure social justice, liberals see a need for fair equality of opportunity for all. Once again, that would require transfer payments in the form of taxes from the haves to the have-nots and that would violate the libertarian’s sacred natural right to property. So we can immediately see one of the ugliest features of a libertarian society: the only children who get an education are those whose parents can afford the tuition for private schooling or who benefit from charity. Nor would there be any public colleges or universities, still less, universal pre-school education or subsidized day-care for the children of working parents. So how serious are libertarians about the right to self-determination? 

One last point: Libertarians are well-known for objecting to governmental rules and regulations as yet another unnecessary restriction on people’s liberties. Sometimes they make the empirical point that regulatory bodies are open to capture by the very parties they are supposed to be regulating. No liberal would deny the point but that hardly shows regulatory bodies are necessarily bound to fail. More interesting is the conceptual point they sometimes appear to make: that regulations per se are restrictive of liberty. This is a dogma. Rules can liberate, provided they are intelligently made and judiciously administered. Just to take one example out of many, consider consumer protection laws. Given the technological complexity of the products consumers buy and the food and drugs they consume, it would be absurd to expect everyone to be their own safety control officer. Life is way too short for that. The information provided by properly done consumer protection laws can be highly liberating.

Contemporary libertarians may regard these arguments as shopworn and out of date. Maybe so, but I still hear them in political campaigns and the speeches of Congresspersons.

Clifford Anderson

Department of Philosophy

Sacramento State