An Essay Concerning Human Understanding by John Locke is one of the great books of the Western world. It has done much to shape the course of intellectual development, especially in Europe and America, ever since it was first published in 1690. Few books have ever been written that have so adequately represented the spirit of an age or left so great an imprint on so many different fields of inquiry. Although the main subject matter of the Essay is primarily a philosophical one, it has had a direct bearing on such areas of thought as education, government, ethics, theology, and religion. Indeed, there are few disciplines in the field of higher education that have not been influenced to some extent by the ideas set forth in this monumental work.
The importance of the book is well indicated by the number of editions that have been published. Between the time of its first publication and the author's death, four editions had been printed, and since that time more than forty editions have been published. Scholars in each succeeding generation have become acquainted with its contents, and in many instances they have made replies in book form to the arguments presented in it.
Because the Essay deals with a subject that is of vital concern to every field of knowledge and because the author was held in high esteem by authors and men of affairs who were contemporary with him, the book became at once the subject of criticism and the occasion for many vigorous controversies. This was in a sense what Locke had hoped his writing would accomplish. He was not a dogmatist, and he made no pretense of possessing a store of wisdom to be passed on to others. Rather, his purpose was to stimulate others to think for themselves, and what he had to say was intended as a means toward that end. In fact, it was one of Locke's major ambitions in all of his writings to dispel the sources of intolerance and encourage people to promote the cause of freedom in their thinking as well as in their actions. Many of the freedoms of which we boast in the Western world today are due in no small measure to the work of this man.
Among the critics who have expressed their views about Locke's work in writing, one finds both praise and condemnation. This is due in part to the fact that not all of them have interpreted what he had to say in the same way. Each critic has viewed the work from the perspective of his own experience and understanding. Each one has come to it with his own presuppositions, and these have been bound to influence the judgments made concerning it. To some extent, this is an unavoidable procedure, and one must deal with it in the best way that he can.
The Essay Concerning Human Understanding was the first work of its kind to appear in modern times. It was an attempt on the part of the author to make a serious and systematic inquiry in the problems of epistemology. It marked an important beginning, for once the inquiry had been brought to the attention of a reputable group of scholars, it became the central issue in the philosophical discussions that took place during the next one and one-half centuries. In fact, the movement that began with Locke was continued by Berkeley, Leibnitz, and other writers of distinction. It reached in one sense a culmination in the philosophies of Hume and Kant.
After Kant, interest in epistemology was replaced to a considerable extent by other topics, which dominated the field until the early part of the twentieth century. After the close of the First World War, a new interest was developed in questions concerning the nature and limitations of human knowledge, and once more the problems that were discussed in Locke's book were given consideration by scholars who were working in many different areas of human experience. While it is true that many of Locke's conclusions are rejected by philosophers of the present time, the spirit of his inquiry may still be regarded as a dominant characteristic of the thinking of the present day.
Any adequate appreciation of Locke's work must take into account the circumstances under which the book was written, as well as the major objective that the author had in mind. Many of the criticisms that have been written about it appear to have overlooked one or both of these points. For example, it has been fairly common among Locke's critics to call attention to the fact that incongruities can be found among the different sections of his work. That instances of this kind can be found when one reads the entire book must be admitted by anyone who has read it with care. But at least a partial explanation for this fact can be seen in the way in which it was composed.
The Essay was not the product of a continuous period of writing. It was produced a little at a time over a period of more than twenty years. Obviously, some changes and modifications were bound to take place as Locke gave added consideration to the questions that were involved. Besides, he made it abundantly clear throughout the Essay that he had no intention of speaking the last or final word on the subject. All that he intended to do was to set down the best thoughts that had come to him at the time of his writing. This he did with the hope that it would stimulate others to carry on a similar inquiry in their own minds.
In an epistle to the reader which forms a kind of preface to the book, Locke tells us how it was that he became interested in this type of inquiry. It all began in a series of discussions that took place in the company of a small group of friends who had been meeting at regular intervals to exchange with one another their views on important questions of the day. Evidently the topics for discussion included such subjects as science, morals, religion, and their relation to one another and to other disciplines. The fact that the members of the group seldom reached any agreement among themselves and often failed to reach any definite conclusions at all caused him to wonder just what benefits, if any, these discussions might have. The more he thought about it, the clearer it became to him that any progress which might be achieved along these lines could come about only by giving careful consideration to the possibilities and the limitations of the human mind.
If one could find out what it is possible for human minds to know and what are those areas that cannot be known, then one need not waste time on those questions that cannot be answered. Again, it would be most helpful to find out those areas, if any, of which we can have certain or absolute knowledge, as well as those areas in which we can never obtain more than probable knowledge. It was the pursuit of these inquiries that led to the writing of the Essay. The task that he set out to accomplish was far more difficult than he was aware at first, and reflection on the issues involved over long periods of time led to many changes and modifications.
The Essay as a whole is a lengthy piece of work, and it is not unusual for those who read it at the present time to become lost in the detailed accounts that are included in it. Many of the words that are used are ambiguous in their meaning, and the ways in which they are used are not always consistent with one another. Further difficulties arise from the fact that words do not necessarily have the same meaning today that they did at the time when Locke wrote. His purpose was the very practical one of helping people to think more clearly about the problems of everyday living, and as a means toward this end he used language in the sense in which it was generally understood at that time.
Technicalities in connection with the use of language with which we are familiar at the present time were not recognized by the average reader in Locke's day, and this accounts for some of the misunderstandings that have occurred in connection with the interpretation of his writings on the part of more recent critics. But these difficulties are relatively minor and should in no way obscure the major objective that Locke had hoped to accomplish.
The primary purpose that seems to have inspired all of Locke's major writings was his intense devotion to the cause of human liberty. He was unalterably opposed to tyranny in any of the forms in which it had been manifested. This included not only political tyranny but moral and religious tyranny as well. The age in which he lived had witnessed the results of tyranny on the part of both political and religious institutions. In the field of government, tyranny had been supported by the theory of the divine right of kings. In a somewhat similar manner, the authority and prestige of the church had been used to coerce individuals into acceptance of what they were told to believe and to do. To all of these devices for controlling the minds and activities of men, Locke was opposed. His views found eloquent expression in his Treatises on Government and his Letters on Toleration. The same objective, although expressed in a more indirect fashion, can be attributed to the Essay Concerning Human Understanding.
Because the freedom of the individual to think and to act for himself necessarily entails a sense of responsibility to exercise these freedoms in the best possible manner, anything that would help to prepare people for this task would be in order. As Locke saw it, nothing would help them more in this respect than a better understanding of the processes that enable human minds to arrive at truth. Furthermore, an appreciation of the limitations of the human mind would encourage an attitude of tolerance toward individuals holding different and conflicting opinions. Tolerance in human society would tend to be a safeguard against persecution and the evils that are necessarily associated with it.