The subject matter of Book III is the use and the abuse of words. It is the shortest of the four books included in the Essay, and its primary purpose is to deal in a more direct manner with some of the problems that emerged from the accounts given in Book II concerning the formation and significance of complex ideas. One of these problems, as we have noted before, is the one that has to do with the question of personal identity. How can one be said to be the same person when all of the particular facts connected with both his physical and his mental existence have changed a number of times? This is but one instance of the larger problem that involves the meaning of all general or universal ideas.
Philosophers of the rationalist tradition had always insisted that universal ideas stand for actual realities. This position had been maintained in two different ways. According to one of them, universals have an existence that is completely independent of particular things. According to the other view, they are realities which are always present in things but do not exist apart from the particulars in which they are expressed.
Locke's theory of knowledge rejects both of these views and advocates instead that only particular things are real. For this reason, it seemed to him to be most appropriate that he should clarify his own position with reference to universals and set forth as clearly as he could the reasons upon which it was based. To accomplish this purpose, he found it necessary to discuss at some length the ways in which words are used and to point out the confusion that results when their proper use is not clearly understood. In making this kind of a report, he became one of the pioneers in the development of what is known as the philosophy of language.
In the opening chapters of this book, Locke describes in brief the origin and function of language, pointing out the way in which particular sounds and signs acquire their first meanings. They are used to refer to that present in the minds of other people and also to refer to external objects, or what is usually called the reality of things. Once a word has been learned, it tends to excite in the mind the object to which it refers. This naturally suggests to anyone that there is some necessary connection between the word and the object for which it stands.
This, according to Locke, is a mistaken notion. He insists that the connection is one that is chosen arbitrarily, and from this we may conclude that the meaning of a word is nothing other than what the individual who is using it wants it to mean. In other words, we may say that signs and sounds derive their meanings solely from their use.
Chapter 3 is devoted entirely to a discussion of the meaning of general terms. Because they constitute by far the kind of words that occur most frequently in the development of any language, it is especially important to indicate just what it is to which they refer and what it is to which they do not refer. The formation and use of general terms, we are told, comes about because of the impossibility of finding a name for every particular object about which we wish to make some communication. Even if this were possible, it would only add confusion to any attempt on the part of one person to convey his ideas to the mind of another.
For language to become a meaningful instrument of communication, it is necessary for some words to be used to refer to whole classes, or groups of objects, which have certain qualities in common. By giving a name to those qualities that are always associated in sense perception, we can designate a whole group of objects without stopping to take into account the various respects in which each member of the group differs from other ones. It is in this manner that we arrive at such class names as metal, chair, man, animals, tree, house, and so forth.
The important thing to remember in this connection is that the name which is given to designate a class of objects is purely a creation of the mind. Although it serves a useful purpose in enabling persons to communicate with one another, it does not refer to any object in itself that may be thought of as having an existence independent of the mind. By giving this account of the formation of general or universal ideas, Locke expresses his opposition to the time-honored doctrine of essences, which had prevailed among most scholars since the days of Aristotle.
According to this doctrine, the species of humans and animals as well as that of all created things is something that remains constant, and all of the particular examples included in each class of objects are only partial embodiments or imitations of the ideal reality for which each class name stands. One of Aristotle's illustrations of this doctrine can be seen in what he had to say about the species of plants and animals. He commented on the fact that nature appears to have a high regard for the species inasmuch as they remain constant in spite of all the changes that occur in the individuals through which the species is made manifest in the world of our experience.
This doctrine, which has frequently been referred to as that of "the immutability of the species," was accepted by the majority of scientists in Locke's day. It was not challenged in any serious way on scientific grounds until the publication of Charles Darwin's Origin of Species. Locke's analysis of universal ideas constituted a challenge on philosophical grounds. His position is well indicated by the words with which he concludes this part of the discussion. He says, "all the great business of genera and species, and their essences amount to no more but this: — That men making abstract ideas do thereby enable themselves to consider things in bundles." This enables them to communicate with one another more readily than would be possible if their words and thoughts were confined to particulars.
The use of general terms is necessarily involved in the making of definitions. On this point Locke tells us that simple ideas cannot be defined. The reason for this is that each one is unique, and any attempt to make a definition of it would consist in stating what it is in terms of what it is not. The situation is quite different in the case of complex ideas, which are derived through the processes of combining, comparing, and abstracting. Here the mind has the power of creating new ideas that did not have any prior existence.
In the case of simple ideas, we naturally tend to think of an external object that has caused the sensation, but there is no object of this kind that produces complex ideas. When a name is given to any complex idea, it may suggest that there is an essence or entity of some sort that corresponds to it. However, we have no evidence to indicate that anything of this nature has any real existence outside of the mind which has created it. The name given to the complex idea does have a definite signification, and for this reason it can be used for the purposes of an inter-personal exchange of ideas.
Locke's position regarding the meaning of general terms is made especially clear in a chapter entitled "Names of Our Ideas of Substances." He rejects the view that ideas of substances refer to essences which belong to the natural order of things. On the contrary, he maintains they are complex ideas that have been formed by the activity of the mind and given specific names, which makes it possible for one person to communicate with another about the particular ideas that he has in mind. While the naming of these ideas may carry the suggestion that they refer to entities which have been placed by nature in the external objects, a careful consideration of the facts will indicate that this is not the case.
The limitless number of variations which distinguish the individual members of any given species makes it evident that nature does not have a fixed pattern or form which is imposed on the individual members of a class of objects. Rather, it is the mind of the person who is trying to understand the objects of his experience that determines what constitutes the essences of things. This is done by selecting the similarities that one observes in a number of these ideas and attaching a particular name to them.
The fact that different people do not always select the same number of similarities is the reason why one person's understanding of what is included in a given essence does not always coincide with that of another person. The selections are more or less arbitrary, and they are conditioned in each case by the purpose for which they are made. The more general the nature of the substance that is named, the greater will be the amount of variations that this name will suggest to different minds. In the case of artificial substances in which the specific elements that are included can be named, there will be a greater degree of similarity in the minds of different people than will be true when one is speaking of natural substances.
In his discussion of the abuse of words, Locke makes a number of important observations. There is nothing that hinders the acquisition of genuine knowledge any more than the failure of people to use words in the proper sense of their meaning. Before Locke's time, Francis Bacon had attempted to deal with this problem by insisting that the idols of the cave, market place, tribe, and theater should all be swept from the human mind. Locke appears to have been influenced a great deal by the general trend of Bacon's philosophy, which is especially evident in what he has to say about the abuse of words and the remedies that may be used to correct it.
Among the abuses of words against which Locke warns his readers is the use of words that have no definite or specific meaning. Apparently he has in mind the way philosophers of medieval times would attempt to solve difficult problems by the use of some term the meaning of which was so obscure that in-stead of providing an adequate solution for the problem it did nothing more than give it a new name.
Another abuse consists in the use of words to which some definite meaning has been attached in the past but which is now used in a very different connection and conveys a meaning that is other than the one for which it was originally intended. In some instances, this second usage will have no definite meaning at all. This is often the case when people use such words as wisdom, glory, grace, or liberty. Sometimes words are used when certain names have been learned before one understands the ideas to which they belong. As a result, there is a lack of constancy in the meanings attached to them.
Several other misuses of words are described and illustrated, but the one which Locke is especially concerned to warn against is that of taking words to stand for things when in reality they signify nothing but ideas. This is what occurs when the names of essences are interpreted to refer to actual entities which have an existence that is independent of the mind.
The remedy for these abuses of words is fairly obvious from the description of the ways in which they occur. However, Locke's statements concerning the remedies to be used are interesting even if they are not always consistent with the nominalistic position he has tried to maintain. He tells us, in the first place, that no word should be used without having some distinct idea annexed to it. When words are used to signify complex ideas, they must be determinate in the sense that they refer to a specific combination of simple ideas. This is especially important in the case of moral terms to avoid ambiguity in the use of words such as justice or righteousness. In the names of substances, we need something more than barely determined ideas: "In these the names must also be conformable to things as they exist."
It is also important to apply words to such ideas as one finds in common usage, and in those instances where one wishes to depart from common usage, he must make clear the precise meaning that he attaches to the words used. This may be done by the use of definitions and also by giving examples to illustrate the meaning one has in mind.
Book III is an attempt to account for the origin and meaning of universal terms without departing from the principles set forth in the earlier parts of the Essay. Having rejected the doctrine of innate ideas and having advocated the view that all knowledge comes from experience, the author found it necessary to explain the true meaning of those ideas that refer to something other than the changing and transitory elements of sensation and reflection. These elements are of momentary duration, but general terms and universal ideas refer to something that is at least relatively permanent. At any rate, they signify something that does not change as quickly or in the same manner as sensations.
How then can one account for the meaning of universals without resorting to the view that they have been implanted in the mind from some source that is other than experience? Locke's answer to this question lies in his analysis of the way in which words are used. By giving attention to the psychological aspects of the problem rather than attempting to deal with the metaphysical issues that are involved, he initiated the movement which in later years came to be known as the philosophy of language. The importance of this trend in Locke's way of thinking can be understood only in the light of its influence on the course of philosophy during the centuries that followed.
Although Locke was not the first one to call attention to the uses and the abuses of words, his analysis went further than that of Francis Bacon or any other one of his predecessors. This was due primarily to the fact that his account of words and their uses was directly associated with his empirical theory of knowledge. It is true, as many of his critics have pointed out, that Locke did not always accept the logical consequences of the method which he had adopted. Because of this, he has been severely criticized for the inconsistencies that are implicit in his epistemology.
Those who are most sympathetic with the quality of Locke's work do not deny the inconsistencies, but they hold that he was too wise a man to allow theoretical inconsistencies to stand in the way of good common sense. They believe he was right in the views that he maintained even though they could not be made to harmonize with the premises on which his whole theory was based. This is the type of thing which has led some people to the conviction that in practical matters, ordinary common sense is more reliable than theoretical speculations no matter how consistent or complete they may be. Locke's inconsistencies in this respect would be regarded by those of a practical turn of mind as evidence of sound judgment on his part.
Nevertheless, any fair appraisal of Locke's work must take stock not only of what he believed to be true but also the adequacy of the arguments that he used in support of those beliefs. It is precisely in this area that the weaknesses of his philosophical position can be brought to light. He wanted to refute the scholastic doctrine of essences and along with it the belief that genera, species, and, in fact, all universals are demarcations of nature to which the ideas in our minds must correspond.
To do this he tried to show how it is that all of these complex ideas are the products of the mind brought about through the processes of combining, comparing, and abstracting. Having created these complex ideas, the mind goes one step further and attaches names to them. The naming of these ideas serves a useful purpose in that it furnishes a means of identification and enables one person to communicate with another in a manner that makes it possible for each of them to know what is in the mind of the other person.
The error which Locke warns against is that of supposing the name stands for an entity in nature; in reality, it is only an idea in someone's mind. Hence, there are no species, genera, or universals in nature. They are only devices that the mind has created to enable a person to understand and to adjust himself to his environment.
It is easy to see that the logical outcome of this line of reasoning can be none other than complete skepticism about the nature of anything that is external to the human mind. Whether there are any permanent patterns or forms of objects in the outside world is something that it is impossible to know. The same thing must also be true with reference to personal identity or selfhood which persists over a period of years. What is generally understood to be a person or self cannot be identified with any single sensation or moment of existence.
There are some passages in the Essay Concerning Human Understanding which indicate that Locke accepted this type of skepticism. He was always anxious to avoid the appearance of dogmatism, and this may have been one of the reasons why in some instances he was careful not to make any definite statement about the nature of the outside world. While he could not deny the existence of universals in nature, he could assert that there is no evidence to support one's belief in them.
There are, however, other passages in the book which indicate quite clearly that Locke was not satisfied with so skeptical an attitude about knowledge of the world. He never abandoned the idea that it is objects in the outside world that cause sensations to appear in human minds. Even in his discussion of the names that are applied to substances, he warns his readers that they must be cautious in the way in which these names are selected and used. With reference to this matter, he says, "In these the names must also be conformable to things as they exist."
One might ask in this connection by what means will it be possible for anyone to know whether the names given to complex ideas are conformable to things as they really exist? Apparently Locke never doubts his own personal identity, the reality of a material world, or the principle of causality as a force or power which produces changes both in the outside world and within human minds. Of course, the logical implications of his basic premises makes it quite impossible to establish the validity of any of these beliefs. Nevertheless, the beliefs may be true in spite of this fact, and there are few persons who would doubt that they are.
The general character of Locke's theory of knowledge indicates that he is contemptuous of metaphysics. Since all knowledge is derived from experience, and human experience is so limited that one can have only partial and fragmentary knowledge about the world in which he lives, any attempt to go beyond the boundaries of human experience and find out something about the nature of the universe as a whole is necessarily doomed to failure. It was with reference to metaphysical speculations that Locke is said to have written to a friend, "You and I have had enough of this kind of fiddling."
In spite of this general attitude, Locke found it impossible to avoid making some commitments with reference to the nature of the universe. He did affirm his belief in God, in the reality of material and spiritual substances, the existence of causal relationships, the moral character of the universe, and other matters all of which are metaphysical in character.