John A. Cagle

Have you ever read anything about language acquisition? That topic is closely related to communication acquisition, so I think it would be profitable to consider one theory in depth. Probably the best theory generated in the 20th Century was the Weldon Theory of How People Get Language:

In heaven there is an Office of Baby Assignments. The Archangel's job is to make sure German-speaking babies get born into German-speaking homes, English-speaking babies get born into English-speaking homes, etc.

This heuristic theory helps explain several other theories. For example, it would provide an explanation for why children develop communicative disorders--the child was simply placed in the wrong home.

Is anything wrong with that theory?

It is not a scientific theory. The purpose of this lecture is to explain what a theory is from a scientific point of view.

The Nature of Science

Theories are essentially statements of what we know about the universe, usually composed of what scientists call laws.

Science is not a method of deducing laws; it is a method of testing them. A lawlike statement is anything that looks like a law. If it looks like a law and it is false, it is not like a scientific law. The difficulty is in knowing what is a true or false law. That is what science is concerned with--differentiating between true and false laws. The laws themselves may come from anywhere; moreover, where they come from is irrelevant.  Stephen Hawking made this compelling observation: 

I don't know of any major theory that has been advanced just on the basis of experiment.  The theory always came first, put forward from the desire to have an elegant and consistent mathematical model.  The theory then makes predictions, which can then be tested by observation.  If the observations agree with the predictions, that doesn't prove the theory; but the theory survives to make further predictions, which again are tested against observation.  If the observations don't agree with the predictions, one abandons the theory.

With acerbic wit, Hawking adds, "Or rather, that is what is supposed to happen.  In practice, people are very reluctant to give up a theory in which they have invested a lot of time and effort.  They usually start by questioning the accuracy of the observations.  If that fails, they try to modify the theory in an ad hoc manner.  Eventually the theory becomes a creaking and ugly edifice."

The important thing to know first off about scientific theories, then, is that the term theory can be applied to a great many different kinds of statements about the universe. The statements themselves do not have to come from science. Scientists can work with a theory that emerges from poetry or fiction; not only can they do so--they often do so.

What does a scientist do? Here is a thumbnail sketch of what a scientist does: A scientist observes reality. He is only interested in things that are kickable. If he can't kick it, it is not work bothering about. A scientist, therefore, observes real events. An event is anything whatever that is kickable. He makes statements to explain what he has observed. Scientists cannot know for sure that they know--but they can have confidence. Any statement that includes "really" is not admissible to science. So the scientist hypothesizes some kind of law; he makes a prediction. Then he tests it to see if the prediction happens.

There is a paradox involved here. A scientist is concerned with reality, but he isn't. The problem is that reality is an insolvable question for a scientist. He finds that he can't fruitfully be concerned with truth in functional existence; he can only be confident that statements make sense. "What is attitude really like?" is a scientific nonsense question. "Does the earth really revolve around the sun?" is a nonsense question. No observation whatever could "prove" either statement beyond all doubt. But the rule that "The earth goes around the sun" is a rule that provides a logical, simple equation to explain or represent our observations of astronomical phenomena.

Weldon's First Law of Science is, Any concept of really is a nonsense question. [Lloyd Weldon generated "First Laws" all the time on practically everything, by the way.] The scientist is only allowed to deal with real events, even though it is impossible to know if the event is real really. Scientists, being practical men and women, have decided not to trust anybody, not even themselves. Which leads us to Weldon's Second Law, A scientific conclusion must be replicable by any person whatever. In the Humanities, we study things because nobody ever did it before. In science, we study things because somebody else already did it. We do so to replicate previous results. Think about it. If somebody makes a lawlike statement and says it is true, then it will be true every time somebody tests it. Because we don't trust one another, we insist that anybody's laws be subject to testing. The only laws we don't test are Weldon's First and Second Laws.

Science is fundamentally a way of thinking and it is essentially quite simple. All of science rests upon two very simple ideas: verifiability and corrigibility. If you can understand these two ideas, you can understand science.


The first idea is the verifiability theory of meaning. As Alston describes in his excellent book, Philosophy of Language, the verifiability theory of meaning was introduced by a group of philosophers, mathematicians, and scientists gathered around Moritz Schlick in Vienna in the 1920s; generally, these men are called "logical positivists." Anyway, these men were concerned with the logic of mathematics and science and with giving philosophy a scientific orientation. As we will see, philosophy and science and inextricably connected; indeed, science is subsumed by philosophy--but these topics will be explored later.

The logical positivists felt that philosophy in the past had been largely given over to useless controversy over metaphysical and normative problems that were, in principle, insoluable. For example, the physical universe depends for its existence on an omnipotent spiritual being; no human beings other than myself are really conscious but are very intricate machines; it is possible that the world came into existence five minutes ago complete with records, memories, geological strata, etc., just as if it had existed for millions or billions of years. Like David Hume in the 18th Century, the logical positivists felt that such controversies were fruitless because the participants were not making sense.

In order to clarify this confusion, they first introduced the principle that in order for one to be talking sense, he must be able to specify the way in which what he says can be empirically verified; in other words, it must be possible to specify what observations would count for or against its truth. That is where the idea of "kickable" comes into scientific thinking.

In order for a person to make sense, it must be possible to account for the conditions which will determine its truth or falsity.

Human beings are capable of making a infinite set of statements, or so we believe. Is that statement verifiable or is it a nonsense statement? Only statements that are empirically verifiable are interesting to a scientist.

Consider again the Weldon Theory of How People Get Language:

In heaven there is an Office of Baby Assignments. The archangel's job is to make sure German-speaking babies get born into German-speaking homes, etc.

It may be important to distinguish between verifiability and verification. In establishing verifiability as an imperative of science, we are not saying that only statements which have been verified are meaningful. No, there are perfectly meaningful statements which have not yet been tested, and even meaningful statements we are not now in a position to test. In requiring verifiability, the logical positivist is simply requiring that it is possible to specify what an empirical test would consist of--he is not requiring that the test have been carried out.

Verifiability, then, is the possibility of verification. Fifty years ago we were not in a position to test the statement, "There are mountains on the other side of the moon," or the statement more interesting perhaps, "The moon is made of green cheese." To a scientist, neither statement is nonsense! Both statements are capable of verification. Indeed, both have been tested. While published reports have settled the first question, is it possible that the Apollo astronauts weren't even a little curious about the question of cheese on the moon? Scientifically, a statement may be wrong but still "make sense" as a question.

A more apt description of verifiability would be the "confirmability criterion of meaningfulness." A scientist requires the specification of observations that would count for or against a statement, which would confirm or disconfirm it to a certain extent. Note that confirm does not mean that a statement is verified in the sense of being true or that a statement has been proven.

The criterion of verifiability is one of the ideal goals of scientific theory building. How nice it would be to have a theory composes of no nonsense statements! It is an aspiration, however, and we must recognize that we cannot always be equal to the task, particularly when we are only in the initial stages of theory building such as we are in the study of human communication.

In a chapter in Emmert and Brooks' Methods of Research in Communication, Kibler writes about a type of construct called hypothetical or theoretical constructs. For example, he wrote, "Constructs that do not possess operational definition must be linked indirectly with observable data by other constructs possessing operational definition." What does he mean by that?

In science, operational definition is one method by which the verifiability of the concepts and statements can be demonstrated. Obviously, a scientist would not use a hypothetical construct if he had a kickable concept to use instead. Many times the problem is simply that not enough is known and some holes in our knowledge have to be filled in so that what we do "know" makes sense. We must conceptualize a construct to show the relations among the events or objects or concepts we have observed. Kibler writes in this connection, "Sometimes behavioral scientists use constructs to refer to an entity or process inferred as actually existing (though not completely observable at present), containing some empirical support, and giving rise to measurable phenomena (phenomena other than the observables that led to postulating the construct). 'Attitude' is an example of such a construct."

If scientific knowledge is built upon empirically verifiable statements, what are the implications of admitting statements of this sort, those which are not kickable or observable? Again we have a type of contradiction. On the one hand, our theories are not quite so amenable to confirmation or disconfirmation, so we cannot have the confidence in them as we would if we had a theory composes of wholly verifiable statements. But on the other hand, there are gaps in our knowledge, sometimes so large that they cannot be simply ignored; it is sometimes necessary that a construct of a hypothetical nature be created to satisfactorily explain what we do know.

An important consideration in this regard is pragmatism. Bertrand Russell thought it a fruitless activity to argue whether a chair exists when we are not looking at it. He said in essence, so long as it is necessary, then it is. The logical positivist asks about any statement whose meaning is in doubt: Is it possible to establish the truth of the statement, and, if so, how would we go about doing it? The pragmatic version of semantic empiricism, as Abraham Kaplan calls it in The Conduct of Inquiry, takes another tact. It asks instead, what difference would it make to us if the statement were true? The meaning of the statement lies in these implications. The test of meaningfulness is simply whether we can make something of a statement, whether it could conceivably matter to us; and a statement's meaning lies in the difference it makes.

Kaplan wrote, "The distinctive contribution to methodology of the pragmatic version of semantic empiricism lies . . . in this: If meanings are to be analyzed in terms of action, they must make reference sooner or later to the ordinary objects and situations which provide the locus of action."

While I may take this quotation slightly out of context, but not out of the spirit of Kaplan's discussion, I think it shoes the importance of pragmatism in our philosophy of science. At once, it insists that our statements be relevant to the world, and also provides a logical basis for the inclusion of constructs which are not directly observable where necessary.

The first idea common to all science is that of verifiability, which means that one must be able to specify (not necessarily to demonstrate) what would determine the usefulness of any scientific statement. In this sense, science is grounded in empiricism; no inherently unobservable phenomenon can meet the criterion of verifiability. This imperative insists that all statements in science must be amenable to empirical tests--at least conceptually.


The second idea at the root of science has to do with that characteristic of scientists not trusting other people. More accurately, it has to do with the self-correcting character of scientific knowledge. The process of science acts to eliminate from the body of scientific knowledge those statements which have been disconfirmed. That is, a statement is tested by making a prediction about a phenomenon, observing that phenomenon, and confirming or disconfirming the prediction. In common language, when we talk of this characteristic of scientific knowledge, we are talking about its reliability. In more sophisticated terms, we are concerned with the concept of corrigibility.

Corrigibility is the insistence that any hypothesis, however well-confirmed, no matter who did the confirming, may be susceptible to disconfirmation in the light of future investigation. Corrigibility is what makes science superior to all other epistemological methods. Richard Rudner, in Philosophy of Social Science, presents the argument to support that statement:

The books, so to speak, are never closed on any hypothesis in the precise sense that evidence relevant to the confirmation or disconfirmation of it can never be exhausted. Accordingly, it is fair to say that if a hypothesis we accept is false, the continued application of scientific method to its investigation will increase the likelihood that we will be able to correct our error by coming upon evidence that disconfirms it. It is in this sense, of a systematically built-in mechanism of corrigibility, that the intellectual history of the species has presented man with no more reliable . . . method of inquiry than that of science.

The scientific attitude is such that disconfirmation is not only permitted, but welcomed. That is not to say scientific people are always happy when their hypothesis is shown to be false. As Campbell and Stanley poignantly pointed out, "For the usual highly motivated researcher the nonconfirmation of a cherished hypothesis is actively painful." The lack of sophistication in our theories and techniques of measurement, moreover, make it likely that we should expect our hypothesis to be disconfirmed rather than confirmed. Nevertheless, when you put all the time and effort and money into your Great American Experiment, you get mad and angry when the computer analysis of your data says you just got a disconfirmed hypothesis, and then you feel sorry for yourself. Of course that happens! That reaction is a human reaction, however, not a scientific reaction. There are times when it feels good to have a cry, but then you've got to get back to the business at hand.

Corrigibility is the concept that provides the justification for a replication study--that is, when you more or less repeat a study which had been done previously. Bowers and Courtright wrote, "Science claims to be a cumulative, self-correcting enterprise, so the scientist's studies must be public and replicable by other scientists."


Science and Communication Theories

So far I have discussed two basic ideas of science. What are their implications for communication theories? You of course can think of some of your own and you should. Here are some that some to my mind.

The verifiability principle insures that a communication theory will have predictive power. If it is possible to specify conditions of truth or falsity, it is possible to derive statements about future events. A theory which implies nothing about the future is comparatively useless. Verifiability insists that any statement in the communication theory imply something about the state of the world, which is basically what prediction is in science. A communication theory without predictive power would be of little use to communication scientists or anybody else.

The corrigibility principle insures that communication theories we develop will be self-correcting. A theoretical system with such an attitude may never be perfect, but at least it will never suffer the consequences of insulating a false statement from change forever.


The Nature of Theory

What is a theory?

Science can be looked at as both a process and a product. As process, science is used to refer to the activities and workings of scientists or scientific institutions--to all the experimenting, observing, reading, reasoning, computering, organizing research projects, and all the other things we have come to associate with the business of science. Science is also used to refer to a result of these activities or processes, to the product of scientific activities--that is, to a corpus of statements purporting to describe one or another aspect of the universe and embodying what counts as our scientific knowledge. It is this latter view of science we should keep in mind.

The methodology of a scientific discipline is not a matter of its transient techniques but its logic of justification. While the hammers and nails and semantic differentials used by scientists may differ from science to science, all of science is characterized by a common logic of justification in its acceptance or rejection of hypotheses or theories. We have already discussed verifiability and corrigibility as two of the imperatives of science. We will now discuss theory in science.

Richard Rudner wrote that "it is salutary to remember that no amount of methodological clarity or rigor or sophistication, however helpful or needed, will suffice for the tasks of description, explanation, and prediction. Accomplishing these tasks in the ineluctable province of substantive theory in science."

Rudner's statement points to the great importance of theory in science. All that is involved in the process of science is for something we presume. The question is, what is it for? A simple explanation is to say that the process of science is to answer questions about the world, but we can go deeper into it than that.

Rudner's point is that while social scientists are generally sophisticated in their methodological rigor, the fact remains that there are few "well-articulated, well-confirmed, comprehensive" theories in the social sciences. One could draw the conclusion that social scientists have been seriously employed in the business of science, but have tended to ignore the essential purpose of the business; they have been concerned with the process of science and little interested in the product of science.

The ideal of science is to give an organized account of the universe--to observe the infinite complexity of phenomena and attempt to formulate a systematic description of the lawlike regularities of the phenomena such that adequate explanation and prediction can be achieved. A scientist must not only collect and analyze data, he must attempt to integrate and synthesize his conclusions into a systematic set of statements that elucidate the phenomena of interest and hence provide understanding, meaning, explanation, and prediction.

Donald Darnell described theory this way: "A theory is a set of statements, including some lawlike generalizations, systematically and logically related such that the set implies something about reality. It is an argument that purports to provide a necessary and sufficient explanation for a range of phenomena. It must be capable of corrigibility--that is, it must be possible to disconfirm or jeopardize it by making observations. A theory is valuable to the extent that it reduces the uncertainty about the outcome of a specific set of conditions."

Thus, a theory is a scientific account of phenomena. At a minimum it is a strategy for handling data in research, providing a conceptual system for describing and explaining. It includes an identification of the components or conceptual categories by which we classify the elements of a system; a specification of the characteristics of these components; and a specification of a set of laws in conformity with which states of the system precede or succeed each other, or with which the components of the system interact. In other words, a theory identifies the elements of the phenomena (as categories, variables, factors) and identifies functional relationships among these elements.

The ideal goal of science is theory. A scientist does many things. He observes, abstracts, categorizes, conceptualizes, generalizes, tests, and so forth--but in the end he hopes to formulate a theory. He may engage in experimentation to test hypotheses, to establish the connection between his theory and the world, but he ultimately must attempt to integrate and synthesize his conclusions into a systematic set of statements that elucidate the phenomena of interest and hence provide understanding.

Without theory, all the endeavor of the process of science is without definition and is therefore meaningless. Meaningless is, of course, a bold statement; it is intended to be viewed in terms of the long-range achievement of the function of science, but one must recognize that "low-level laws" can be useful, even if not broadly applicable. My argument is that theory provides the focus, the unifying conceptualization, the road from the hypotheses to the real world, the center of activity, the impetus for the pursuit of knowledge.

I want to emphasize the connection between science and philosophy. If scientific theory building sounds much like developing a philosophical treatise, it is because science is subsumed by philosophy. It is not by accident that the highest degree a university awards in any subject area is called a "Doctor of Philosophy" degree. Philosophy concerns the theory of knowledge--epistemology; there is another branch of philosophical discipline which concerns the moral questions which man has pondered. However, under epistemology, one is concerned with the character of knowledge and claims about knowledge. Among the various ways of knowing, we have science.

Moral philosophy is not the aim of science. Put another way, the aim of science is not the betterment of mankind. The aim of science is theory--that is, knowledge. It is the province of other branches of philosophy, including perhaps theology, to decide what is to be done with that knowledge. Should Einstein and other scientists have worked on the atomic bomb? Certainly the development of nuclear weapons with the potential to destroy mankind has been brought into question. But as scientists, once a question has been asked, the scientist must seek an answer to it. But as a human being, a moral person, a right thinker, an ethical man, whatever--maybe certain questions shouldn't be asked or answered. That is not a question of science--it is a moral question. To be effective human beings, it is probably best to keep the "total man" in mind. Some of you may become scientists, but you should also be human. Plato objected to rhetoric because it could be used to persuade people of evil things. Aristotle asserted that rhetoric was amoral; knowledge was knowledge, people could do with it as they chose, good men ought to be armed with knowledge as well as evil, etc.

Scientific communication theories do not present views about how communication should occur in the world. Rather, they attempt to explain and predict the way communication does occur.

What I am trying to suggest here is that there are many popular feelings about products of science. You should not let them obscure your understanding and appreciation of the value of scientific theories. On the other hand, you should not let science obscure your understanding of what it means to be human and of what man ought to be doing if he is to be humane.



Alston, William P. Philosophy of Language. Englewood Cliffs, N.J.: Prentice Hall, 1964.

Bowers, John Waite, and Courtright, John A. Communication Research Methods. Glenview, Il.: Scott, Foresman and Company, 1984.

Emmert, Philip, and Barker, Larry L., eds. Measurement of Communication Behavior. New York: Longman, 1989.

Emmert, Philip, and Brooks, William D., eds. Methods of Research in Communication. Boston: Houghton Mifflin Company, 1970.

Hawking, Stephen.  Black Holes and Baby Universes and Other Essays.  New York:  Bantam Books, 1993.

Kaplan, Abraham. The Conduct of Inquiry. San Francisco: Chandler, 1964.

Kerlinger, Fred N. Foundations of Behavioral Research. 3rd ed. New York: Holt, Rinehart and Winston, 1986.

Rudner, Richard S. Philosophy of Social Science. Englewood Cliffs, N.J.: Prentice Hall, 1966.


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