Ridling Zaine. Philosophy: Then and Now. A look back at 26 centuries of thought

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Ridling, Philosophy Then and Now: A Look Back at 26 Centuries of Thought

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Philosophy of Mind as a Discipline

In distinguishing the field of philosophy of mind from other sorts of

investigation, one immediately obvious feature is its subject matter, the nature

of mind and its various manifestations. This serves to distinguish it from

empirical sciences such as astronomy and physics, which study matter in

motion; from formal disciplines such as geometry and algebra, which study

mathematical relationships; and from other fields of philosophy such as the

philosophy of art and the philosophy of law. But subject matter alone does not

serve to distinguish the philosophy of mind, since the mind is the subject of

investigation of other disciplines as well – especially of psychology and of

certain phases of biology, physiology, sociology, and anthropology. In

comparison with these fields, it is by its method that the philosophy of mind is

to be distinguished; for it proceeds not by the methods of empirical

investigation – detailed sense observation, the formulation of predictions, the

construction of experiments, inductive confirmation, the inventing and testing

of contingent generalizations, theories, and laws – but by the method of

philosophical reflection. That method consists of the examination of

meanings, the analysis and clarification of concepts, the search for necessary

truths, the use of deductive inference, reductio ad absurdum, and arguments

with infinitely repeating terms and other forms of a priori reasoning, and the

attempt to arrive at and evaluate the fundamental principles that underlie and

justify the basic forms of human thought and endeavor.

Although the philosophy of mind is a distinct field of investigation, it

has many important relations with other fields. First, its methods, being those

of philosophy in general, are to be tested by the fruits that they have yielded in

other areas: if a method has been successful in other areas, it is reasonable to

try it here; if unsuccessful in other areas, it is suspect here. Second, the

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conclusions achieved in such fields as epistemology, metaphysics, logic,

ethics, and the philosophy of religion are quite relevant to the philosophy of

mind; and its conclusions, in turn, have important implications for those

fields. Moreover, this reciprocity applies as well to its relations to such

empirical disciplines as neurology, psychology, sociology, and history. Thus,

the philosopher of mind must keep informed of developments in all related

fields of investigation.

The Search for a Criterion of the Mental

The bewildering variety of phenomena that fall under the heading of the

mind or the mental was suggested earlier in a list. The question arises,

however, whether there is some attribute that all of these mental phenomena

have in common, something that characterizes them or that can serve as a

criterion of the mental. More specifically, are there certain features that are

either necessary or sufficient for mental phenomena?

Purposeful Behavior

Whenever a man watches a hungry animal using stealth and cunning in

searching out, attacking, and killing its prey, he cannot but believe that the

animal has a purpose and uses intelligence in achieving his goal. Whether it be

a team of scientists designing a way of launching a man to the Moon, an ape

figuring out how to screw two pieces of pipe together to get a banana that is

out of reach, or – at a much lower level – a lobster trying to get out of a pot of

boiling water, there seems to be a mind at work. Somewhere, as the

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phenomenon is traced farther down the ladder in the scheme of things toward

inanimate matter, a line must eventually be drawn; but there is no agreement

about where it should be drawn. It would be widely agreed that an ovum that

has just been fertilized does not have a mind and that a normal adult does –

but it is impossible to say exactly where in human development the change

occurs. On the other hand, it would be just as erroneous to conclude that

because there is no sharp dividing line there is no change as it would be to

conclude that red and orange are the same color because no sharp line divides

them in the spectrum. In both instances there exists a transitional range within

which the designation of a dividing line would be purely arbitrary; but at

either end beyond that range a clear and definite difference is evident.

The question may then be raised as to how adequate purposeful activity

is as a criterion of the mental. A major issue arises from the fact that a

mechanical device can be built that exhibits the kind of activity ordinarily

called purposeful – a surface-to-air missile, for example, so designed that it

will hunt for a jet aircraft by searching for, and zeroing in on, the heat exhaust,

thereby finding and destroying the aircraft. Such devices, known as

“servomechanisms” (of which a thermostat is a simple example), achieve an

end state by systematically diminishing any deviation from that predetermined

end state. There are, in addition, the modern computers, capable of receiving,

storing, and retrieving information, of making inferences, and of

communicating information. Near the height of modern sophistication in

machine technology are those machines, combining servomechanisms and

computers, designed to roam the surfaces of other planets, gathering,

processing, and sending back data and thus providing what would seem to be

paradigms of purposeful behavior and raising the question whether such

systems are examples of minds at work. There are three possibilities worth

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considering: (1) one might continue to hold that purposeful behavior is the

criterion of the mental but argue that these devices do not really meet the

criterion of exhibiting purposeful behavior; (2) one might hold that the more

complex of these devices do indeed have what can be called minds – simple

and rudimentary, to be sure, but still minds – “artificial intelligences” that in a

very literal sense have beliefs, think thoughts, solve problems, and achieve

goals; or (3) one might give up the criterion of purposeful behavior, or at least

give it up as a sufficient condition of the mental.

Someone defending possibility (1) would attempt to find some feature of

purposeful behavior that could not be found in any mechanical device. He

might hold, for instance, that the alleged purposes of mechanical devices are

built in by their designers and that it is not up to the devices to choose their

purposes. Against this line of argument, however, others might assert that for

a large number of organisms the basic purposes are also built in through the

genetic mechanisms of heredity: basic biological drives for food,

reproduction, and safety govern most of their purposeful behavior. People

who accept this point of view argue that, in most cases, the organism is not

really free to choose its purposes. On this argument, even human beings seem

to display such built-in purposes; and it would be specious, at least in this

instance, to deny them minds on this account.

Conceding that organisms have some built-in controls, the defender of

the first possibility might then argue that the higher organisms have a

flexibility that allows for the development of purposive methods that are

novel. Machines, he would allege, solve problems only by the methods

designed into them, whereas creatures with minds can invent new methods.

Against this line of argument others might argue that machines have been

developed to use trial and error, analyze the outcomes of trends, and come up

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with new approaches that are more successful than earlier ones, and that, in an

important sense, such machines might be called creative, since they “learn

from experience” and use “ingenuity.” Many observers assume that this trend

in machine technology will continue and that machines will be developed with

much, if not all, of the flexibility of many of the creatures that would

unhesitatingly be acknowledged to have minds.

The basic issue, then, is whether a philosopher would want to say that a

machine has a mind if it exhibits the flexibility in purposeful activity of, say, a

normal seven-year-old child, who undoubtedly has a mind. In accepting

possibility (2), the philosopher would maintain that such a machine does

indeed have a mind and exhibits a wide range of the phenomena called

mental. Many contemporary philosophers, however, would reject that thesis,

considering it a needless flaunting of common sense and an affront to ordinary

language to speak of a heat-seeking missile, for example, or even a lunar

robot, as having a mind. Because something essential still appears to be

omitted, further attempts are made below to determine the essence of the

mind.

Intentionality

Another characteristic of the mental is sometimes thought to be found in

certain ways in which an individual may be said to have something as his

object. Thus, thinking, believing, desiring, and other such attitudes are thought

to resemble one another in that they may be said to take an object, or to be

directed upon an object, in a way quite unlike anything to be found in what is

purely physical. “Intentionality” is the term for this way of being directed

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upon an object. The concept had been emphasized by some of the Scholastics

and was introduced to modern philosophy in 1874 by a German philosopher

and psychologist, Franz Brentano, and clarified and defended by a U.S.

philosopher, Roderick M. Chisholm, in the 20th century.

Figure 1: Three arbitrary physical objects in meaningless configuration

Figure 2: Physical objects with intentionality.

The idea of intentionality can be explicated in the following way: if one

imagines three objects arranged as in Figure 1 and then supposes that the wind

blows them so that they are arranged as in Figure 2, there results, from the

physical point of view, simply a new arrangement. From a psychological point

of view, however, something radically new also has been introduced: one

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object now appears to be pointing to another – aimed at or directed toward it.

It would seem that such pointing cannot be accounted for if the observer

confines himself to the purely physical facts of the new configuration and that

his mind has to be brought in to account for the feature of pointing to. Thus,

intentionality is prima facie a reasonable candidate for the criterion of the

mental.

Intentionality is exhibited in a variety of phenomena. Thus, if a person

experiences an emotion toward an object – e.g., loves, fears, pities, envies, or

reveres it – he has an intentional attitude toward it. Other examples of

intentional attitudes toward an object are: looking for or expecting, believing

in, doubting or conjecturing about, daydreaming, reminiscing, imagining,

favoring, or disapproving – a list that seems to go on endlessly. Because it

clearly comprises so many of the things that one thinks of as typically mental,

intentionality, being of broader scope than purposefulness, would seem to be a

more appropriate choice than purposeful behavior for the criterion of the

mental.

One of the characteristics of intentionality is what the Scholastics called

“inexistence”: a man may be intentionally related to an object that does not

exist or to an event that does not occur. Thus, what a man looks for may not

exist, and an event that he believes to occur may not occur at all. In contrast

with such a nonintentional phenomenon as bumping into something, in which

the object bumped into must be real, looking for something (an intentional

act) does not necessarily imply that the object looked for exists. Similarly, in

contrast with an explosion’s resulting in the fact that many were hurt, a

witness believes that many were hurt (again an intentional act) does not imply

the fact that many were hurt. Thus, existence and truth are irrelevant to

intentionality.

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Though this possible relationship to nonexistent objects as opposed to

existent ones is a necessary feature of intentionality, it is not sufficient to

define it, for there are phenomena that are equally concerned with nonexistent

essences that are nonetheless nonintentional. “That lady resembles a

mermaid,” to use an example of Chisholm’s, may be a true sentence even if

mermaids, though having an essence, do not exist. Similarly, “That metal will

ignite at temperatures above 1,000,000’” may be true whether or not such

temperatures exist. Thus, intentionality requires further characterization if its

scope is to be narrowed to exclude such examples as these.

Another characteristic of the intentional state is that not every

description of its object will be appropriate. Assuming that his pen is the

millionth pen produced this year, for example, a man may be in the intentional

state of searching for it as his pen but not in a state of searching for the

millionth pen produced this year; similarly, he may believe this is his pen and

yet not believe that this is the millionth pen produced this year. This second

feature of intentionality, often called “referential opacity,” is such that a true

sentence asserting an intentional state will become false when some

alternative description of the object of that state is substituted for it (it is false

that he is searching for the millionth pen).

There is no general agreement on the best way of conceiving of

intentional phenomena. Brentano, at one point, thought of intentionality as

being a relation between a subject and an entity, in which the entity is

something that might or might not exist; but difficulties arise in characterizing

the ontological status of such an entity – i.e., its kind of reality. More popular

today are certain linguistic approaches: intentionality may be viewed, for

example, as it was by Rudolf Carnap, a philosopher of science, and others, as

a relation between a subject and a piece of language or, as others have

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explained, as a relation between a subject and a linguistic practice or linguistic

role. Under this view, the intentionality consists not in the relation of a subject

to an essence (that of a millionth pen) but in its relation to a sentence (“This is

the millionth pen... “) that has that alleged essence as its meaning. It remains

to be seen whether such approaches will succeed in dealing with all

intentional phenomena. It would seem to pose particular difficulty in those

cases in which the intentional state is overtly directed toward some existent

entity, with language playing a minor or null role, as in situations in which

one feels anger, pity, or love toward someone; or when an animal is stalking

its prey (which involves an intentional state). In such instances, an analysis in

terms of linguistic attitudes would seem wide of the mark.

The Scope of Application of Intentionality

The question of whether or not intentionality can apply to nonliving

physical systems has become a controversial issue. If it can apply, then either

intentionality would have to be given up as an exclusive criterion of the

mental or else one would have to say that such systems exhibit some mental

characteristics.

Figure 2: Physical objects with intentionality.

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It will be useful to consider a system designed for some purpose, taking

the example again of the surface-to-air missile that searches for jet aircraft,

and to ask whether it has intentionality. It does satisfy the first characteristic

mentioned above: that it can be truly said to be a jet searcher regardless of

whether there are or have been any jet aircraft (one could similarly design a

unicorn searcher built to detect unicorns by their special horn). The question

next arises whether some descriptions of the object are inappropriate. On the

supposition that all and only jet aircraft have a component made of compound

X, one can ask whether it would be true of the missile that it searches for

things with a component made of compound X. It would seem that – unless

this compound chances to be what the search system was sensitized to – the

foregoing statement is a false, and thus an inappropriate, description of the

device; and if so, it is plausible to regard the missile as a physical system with

intentionality as that notion has been here characterized. An intentional

physical system, however, would have to be of considerable complexity. One

would not want to say that the left-hand complex in Figure 2 was pointed to

the right-hand figure unless he had in mind that, if the right-hand figure were

to shift its location, the left-hand complex would shift appropriately. If it did

keep shifting appropriately, however, it would seem proper to say that it

points to the right-hand figure. The question remains, however, whether all

intentional phenomena are capable of appearing as instances in nonliving

physical systems – whether such a physical system could have, for example,

an emotion toward something, daydream about something, or be amused by

something. Here it is very difficult to cite a plausible case; it would appear

that one would have to strain such concepts considerably to apply them to

nonliving systems.