An Essay Concerning Human Understanding Analysis

John Locke


(Student Guide to World Philosophy)

John Locke’s An Essay Concerning Human Understanding is the first major presentation of the empirical theory of knowledge that was to play such an important role in British philosophy. The author had studied at Oxford, and later he became a medical doctor. Although he did not practice much, he was greatly interested in the developments current in medical and physical science, and there is some evidence that he first began to formulate his theory of knowledge in terms of considerations arising from medical researches of the day. Locke was a member of the Royal Society of England, where he came into contact with many of the important experimental scientists, such as Robert Boyle and Sir Isaac Newton. A discussion with some of his friends seems to have been the immediate occasion of the writing of An Essay Concerning Human Understanding, in which Locke attempted to work out a theory of knowledge in keeping with the developing scientific findings and outlook.

The completed version of the work dates from the period when Locke, along with his patron, the Anthony Ashley Cooper, the third earl of Shaftesbury, was a political refugee in Holland. After the Glorious Revolution of 1688, Locke returned to England and was quickly recognized as the leading spokesperson for the democratic system of government that was emerging in his homeland. The essay, first published in the same year as Locke’s famous work in political philosophy, Two Treatises of Government, quickly established the author as the foremost spokesperson for the new empirical philosophical point of view that was to dominate English philosophy from then on.

An Essay Concerning Human Understanding Seeking the Origins of Human Knowledge

(Student Guide to World Philosophy)

The question to which Locke addressed himself in his essay is that of “the origin[s], certainty, and extent of human knowledge, together with the grounds and degrees of belief, opinion, and assent.” By using what he called “this historical, plain method,” Locke hoped to discover where our ideas and our knowledge come from, what we are capable of knowing about, how certain our knowledge actually is, and when we may be justified in holding opinions based on our ideas. The value of such an undertaking, Locke asserted, is that one would thus know the powers and the limits of human understanding, so that “the busy mind of man” would then restrict itself to considering only those questions with which it was actually capable of dealing and would “sit down in a quiet ignorance of those things” beyond the reach of its capacities.

Before commencing his investigations, Locke pointed out that human beings do, in fact, have adequate knowledge to enable them to function in the condition in which they find themselves. Therefore, even if the result of seeking the origin, nature, and extent of our knowledge leads us to the conclusion that we are unable to obtain complete certitude on various matters, this should not be grounds for despair, for skepticism, or for intellectual idleness. People have wasted too much time, Locke insisted, in bemoaning their intellectual situation or in disputing in areas in which satisfactory conclusions are impossible. Instead, he said, we should find out our abilities and our limitations, and then operate within them.

An Essay Concerning Human Understanding The Question of Innate Knowledge

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The first book of An Essay Concerning Human Understanding deals with one theory about the origin of our ideas, the thesis that our knowledge is based upon certain innate principles that are supposed to be “stamped upon the mind of man.” Locke severely criticized this theory, especially in the form in which it had been presented by thinkers such as Herbert of Cherbury. Adherents of this theory of innate ideas had maintained that the universal agreement of humankind regarding certain principles showed that these must be innate. Locke argued in opposition that the fact of universal agreement would be insufficient evidence as to the source of the principles in question. He also argued that, in fact, there actually are no principles that are universally agreed to, since children and idiots do not seem to know or believe the principles that are usually cited as examples of innate ideas. The way in which children acquire knowledge about the principles in question, through the learning process, further indicates that they are not born with innate ideas.

After having criticized the innate idea theory, Locke turned next to the positive side of his investigation. We do have ideas (an idea being defined as whatever is the object of the understanding when a person thinks); this is beyond any possible doubt. Then, if the ideas are not innate, where do they come from?

An Essay Concerning Human Understanding Empirical Origins of Knowledge

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The second book of An Essay Concerning Human Understanding begins the development of a hypothesis about the origins of human knowledge, namely, the empirical theory. Let us suppose, Locke said, that the mind initially is just a blank tablet (a tabula rasa). Where, then, does it obtain its ideas? From experience, Locke proclaimed. Experience comprises two sources of ideas, sensation and reflection. We receive many, if not most, of our ideas when our sense organs are affected by external objects. We receive other ideas by reflection when we perceive the operations of our minds on the ideas that we have already received. Sensation provides us with ideas of qualities, such as the ideas of yellow or of heat. Reflection provides us with ideas such as those of thinking, willing, and doubting. These two sources, Locke insisted, give us all the ideas that we possess. If anyone has any doubts about this, let that person simply inspect his or her own ideas and see if there are any that have not come to him or her either by sensation or reflection. The development of children also provides a further confirmation of this empirical theory of the origin of human knowledge. As the child receives more ideas from sensation, and reflects on them, that child’s knowledge gradually increases.

An Essay Concerning Human Understanding Ideas: Simple and Complex

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Having thus answered the question concerning the origin of our ideas, Locke proceeded to investigate the nature of the ideas that we possess. All of our ideas are either simple or complex. A simple idea is one that is uncompounded, that contains nothing but one uniform appearance, and that cannot be distinguished into different ideas. An example of a simple idea would be the smell of a rose. A complex idea, in contrast, is one that is composed of two or more simples, such as a yellow and fragrant idea. The simples, Locke insisted, can neither be created nor be destroyed by the mind. The mind has the power to repeat, compare, and unite the simples, thereby creating new complex ideas. However, the mind cannot invent simple ideas that it has not experienced. The simples, in the Lockean theory of knowledge, are the building blocks from which all of our complex and compounded ideas can be constructed and accounted for.

Many of the simple ideas are conveyed by one sense, such as the ideas of colors, sounds, tastes, smells, and touches. One crucial case for which Locke argued is the idea of solidity, which he claimed we receive by touch. This idea is that of a basic quality of bodies. It is not the same as the space that bodies occupy, nor is it the same as the subjective experience of hardness that we receive when we feel objects. Instead, for Locke, solidity is akin to the fundamental physical notion of “mass” in Newtonian physics. It is that which makes...

(The entire section is 440 words.)

An Essay Concerning Human Understanding Qualities of Objects

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If these are the types of ideas that we possess, classified according to their sources, can we distinguish those ideas that resemble actual features, or qualities of objects, and those that do not? The qualities of objects are divided by Locke into two categories, the primary and the secondary ones. The primary ones are those that are inseparable from bodies no matter what state the object may be in. This group includes solidity, extension, figure, mobility, and number. In contrast, the secondary qualities “are nothing in the objects themselves, but the powers to produce various sensations in us by their primary qualities,” such as the power of an object, through the motion of its solid, extended parts, to produce sounds, tastes, and odors in us when we are affected by it.

Thus, in Locke’s theory, objects possess primary qualities, the basic ingredients of Newtonian physics, and they possess secondary ones, which are actually the powers of the primary qualities to cause us to perceive features, such as colors, odors, and so on, which are not “in” the objects themselves. In terms of this distinction, we can say that our ideas of primary qualities resemble the characteristics of existing objects outside us, whereas our ideas of secondary qualities do not. The primary qualities of things are really in them, whereas the secondary qualities, as perceived sensations, are only in the observer. If there were no observers, only the primary qualities and their powers would exist. Hence, the rich, colorful, tasteful, noisy, odorous world of our experience is only the way we are affected by objects, not the way objects actually are. This distinction between our ideas of primary and secondary qualities led Locke to argue that some of our ideas give us genuine information about reality, while others do not.

An Essay Concerning Human Understanding The Idea of Substance

(Student Guide to World Philosophy)

In the remainder of the second book of An Essay Concerning Human Understanding, Locke surveyed the various other kinds of ideas that we possess, those gained by reflection, those that are complexes, and so on. The most important, in terms of his theory and in terms of later philosophy, is the complex idea of substance. The idea of substance originates from the fact that in our experience a great many simple ideas constantly occur together. We then presume them to belong to one thing because we cannot imagine how these simple ideas can subsist by themselves. Therefore, we accustom ourselves to suppose that there must be some substratum in which the ideas subsist, and we call this substratum a substance. When we ask...

(The entire section is 444 words.)

An Essay Concerning Human Understanding Ideas and Reality

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At the end of the second book of An Essay Concerning Human Understanding, Locke evaluated what he had discovered about the nature of our ideas. This evaluation commences the examination of the problem of the extent and certitude of our knowledge, which is developed at length in the fourth book. Our ideas are real, Locke contended, when they have a foundation in nature and when they conform with the real character of things. In this sense, all simple ideas are real because they must be the result of genuine events and things (since the mind cannot create them but receives them from experience). However, not all real ideas are necessarily adequate representations of what does in fact exist. Ideas of primary qualities are...

(The entire section is 379 words.)

An Essay Concerning Human Understanding Words and Language

(Student Guide to World Philosophy)

The third book of An Essay Concerning Human Understanding appears to deal with some unrelated topics, those concerning the nature of words and language. This book, which evoked the interest of those concerned with linguistic philosophy, covers problems normally dealt with in anthropology, psychology, linguistics, and philosophy.

Two points that are raised are of central importance to Locke’s main theme of the nature and extent of our knowledge and played a role in the later history of empirical philosophy. One of these is Locke’s theory concerning the meaning and referrent of general terms, such as “man” and “triangle.” All things that exist, Locke asserted, are particular, but by abstracting from...

(The entire section is 369 words.)

An Essay Concerning Human Understanding Knowledge as Comparison of Ideas

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The fourth and last book of An Essay Concerning Human Understanding deals with knowledge in general, with the scope of knowledge, and with the question of how certain we can be of such knowledge. Our knowledge deals only with ideas, since these are the only items with which the mind is directly acquainted. What constitutes knowledge, according to Locke, is the perception of the agreement or disagreement of two ideas. Ideas may agree or disagree in four ways. They may possibly be identical or diverse. They may be related in some respect. They may agree in coexisting in the same subject or substance. They may agree or disagree in having a real existence outside the mind. All of our knowledge, Locke insisted, falls under...

(The entire section is 272 words.)

An Essay Concerning Human Understanding The Problem of Certitude

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We acquire knowledge not only by directly inspecting ideas but also through demonstrations. According to Locke, when we know by demonstration, we do not see immediately that two ideas agree or disagree, but we see immediately by means of connecting two ideas with others until we are able to connect them with each other. This process is actually a series of intuitions, and each step in a demonstration is therefore certain. However, because the steps occur successively in the mind, error is possible if we forget the previous steps or if we assume that one has occurred if it actually has not. Intuition and demonstration are the only two sources of certain knowledge.

However, there is another source of...

(The entire section is 214 words.)

An Essay Concerning Human Understanding The Extent of Human Knowledge

(Student Guide to World Philosophy)

In terms of these kinds of knowledge, types of sources, and degrees of certainty, it is now possible to outline the extent of human knowledge and to evaluate what we can actually know about the real world. We can gain knowledge only to the extent that we can discover agreements or disagreements among our ideas. Because we can neither intuit nor demonstrate all the relations that ideas can have with one another, our knowledge is not even as extensive as our ideas. In almost all cases, we can determine with certainty whether our ideas are identical or different from one another. We can tell if our ideas are related to others only when we can discover sufficient intermediary ideas. In fields such as mathematics, we keep expanding our...

(The entire section is 449 words.)

An Essay Concerning Human Understanding Foundations of Empiricism

(Student Guide to World Philosophy)

Locke’s An Essay Concerning Human Understanding represents the first major modern presentation of the empirical theory of knowledge. In developing an account of human knowledge in terms of how it is derived from experience, what its nature is, and how limited it is, Locke provided the basic pattern of future empirical philosophy. In attempting to justify some basis for maintaining that we can have some knowledge of some aspects of reality, Locke raised many of the problems that have remained current in philosophical discussions up to the present time. Empiricists after Locke, such as Berkeley and Hume, showed that if one consistently followed out the thesis that all of our knowledge comes from experience, one could not...

(The entire section is 162 words.)

An Essay Concerning Human Understanding Bibliography

(Student Guide to World Philosophy)

Additional Reading

Ayers, Michael. Locke. New York: Routledge, 1999. An excellent biographical introduction to the thoughts of the philosopher, clearly presented and requiring no special background. Bibliography.

Brantley, Richard E. Locke, Wesley, and the Method of English Romanticism. Gainesville: University of Florida Press, 1984. Brantley alleges that John Locke influenced John Wesley, the founder of the Methodist Church, and that Wesley’s work influenced the eighteenth century Romantic poets.

Chappell, Vere, ed. John Locke: Theory of Knowledge. New York: Garland, 1992....

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