Lectures on John Locke

Locke is generally considered the first in the line of British empiricists, with Berkeley and Hume adopting his starting point. The fundamental claim is that human knowledge begins with sense experience and primarily is derived from it. Locke begins his philosophical examination of knowledge by trying to refute the claim that some of our knowledge is original, in the sense that it comes from ideas which are innate or inborn. This view was held most prominently by Descartes.

Locke's attempted refutation depends on a questionable assumption: if an individual has an idea, then that individual would understand it and assent to its content. If, as Descartes claimed, I am born with the idea of God, who implanted that idea in me at my creation, then my understanding of what God is should conform to that idea. But Locke points out that there is widespread disagreement over the concept of God. Furthermore, it does not seem to be present at all in small children. In II,I,6, Locke states that we come to our knowledge by degrees.

However, the proponents of innate ideas need not agree to Locke' assumption. Descartes in one place wrote that innate ideas are dispositions, which require the proper circumstances to become fully clear to the mind. Leibniz responded that we can have ideas of which we are not conscious. Thus both disagreed with the fundamental Lockean assumption that to have an idea is to be aware of it.

Locke concluded from his attack on innate ideas that the only way ideas could arise is as the result of sense experience. We form ideas as the endpoint of the action of physical bodies on our own bodies. Locke points out in II,VIII,7 that sometimes he uses 'idea' to refer to the end product, what exists in the mind, and sometimes he uses it to refer to the quality in the body which causes the idea.

The ideas of sense are the first ideas we have. Once the mind begins to be populated with them, it can operate upon them. This operation is the source of a second kind of idea, the idea of reflection. Unlike many ideas of sense, which force themselves upon us, so that we cannot help but be aware of them, all ideas of reflection require that attention be paid to the workings of the mind. Thus Locke says that children and even some adults fail to have ideas of reflection, because they lack the requisite attentiveness to what their mind is doing.

Locke classified ideas as simple and complex. All complex ideas are said to be made up, ultimately of simple ideas, and their complexity is the work of the mind.

A simple idea is "one uncompounded appearance," said Locke. But it should be noted that the relation of simple to complex ideas is not the relation of part to whole. (Berkeley and Hume both thought that there are minimum sensible units, like the dots making up a newspaper picture.) A simple idea is perhaps best described as being of a certain sort or kind. Thus we have a simple ideas of solidity. When I press a football between my hands and feel its resistance to their joining together, I have a simple idea of solidity.

In general, our simple ideas are the effects of the operations of bodies on us (sensation) or the observation of the workings of our own minds (reflection). In a famous passage (II,XI,17), Locke compares the mind to a "dark room" (in the Latin, "camera obscura") with only a narrow inlet. Ideas are analogous to the images projected onto the back of the room.

Locke classified the various simple ideas according to the following scheme.

  1. Those that come to the mind by one sense only, such as color or odor.
  2. Those that come in to the mind by more than one sense. These include extension, figure, rest and motion. (Note that these will later, for another reason, be called "primary" qualities.)
  3. These that come to the mind by reflection only. Perception (in the broad sense of sensibly perceiving, thinking, imagining, remembering) and willing are the two simple ideas of this type.
  4. Those which accompany all our other ideas: pleasure and pain, unity, existence, power, succession. Pleasure and pain will assume importance later because of their role in the motivation of human action. Power is a most fundamental idea, as will be seen. In II,VII,8, Locke notes that we get this idea both from our thinking and from the effects of bodies on one another.
Now let us consider the kinds of powers bodies have. Locke sometimes identifies the qualities corresponding to our ideas as powers. Thus the sun has the power to melt wax, and heat is the quality which brings this about. Call a bare power one by which a body can bring about a change in another body, such as the heat of the sun, which melts the wax. (The wax also has the power to be melted by the heat of the sun.)

Other powers of bodies are such as can produce ideas in our minds. There is are powers in the sun to produce the idea of light as well as the idea of heat and that of roundness and that of yellow. Locke divided these powers (or as he puts it, the qualities of the bodies) into two kinds, the primary and secondary.

The basis of the division is our ability to conceive bodies in general. There are some qualities without which we cannot conceive a body. Thus we must conceive a body as being solid and extended, as having a figure, as being in motion or at rest. These qualities are primary. Other qualities are dispensable. Locke said he can conceive a given body as being neither warm nor cold, as having no color at all (as when it is in the dark).

The distinction between primary and secondary qualities is, at root, a conceptual distinction concerning how we can represent bodies. A primary quality is one which must represent a body as having in every possible circumstance. No matter how small a body is, it has some extension. No matter how fluid it is, it has some solidity, no matter where it is at a time, it must be moving or at rest at that time. Secondary qualities come and go, depending on whether they are in the right relation to a perceiver. An object has color only insofar as it can be seen. If there is no light, there is no color.

To be sure, a body always has a power to produce ideas of colors under the right circumstances, but this power is nothing more than a function of its primary qualities. Thus a body always has a certain texture, due to the arrangement and solidity of its component parts. Locke subscribed to the "corpuscularian hypothesis," according to which bodies are made of indivisible particles. Each of them has all the primary qualities, but they lack secondary qualities. They do not even have the power to produce ideas which we could call their color.

Locke made the further claim that our ideas of primary qualities resemble the qualities, while those of the secondary do not. Berkeley will raise the question how Locke can make any claim of resemblance, given that he has no data other than the ideas themselves, and hence cannot compare them to their supposed originals. Locke seems to have held the resemblance view because he could not conceive of bodies any other way.

The claim of the non-resemblance of the ideas of secondary qualities and their originals requires further argument. Even if there are conditions under which bodies lack the qualities, why say that when they do produce the ideas, say of their color, what produces them is not colored? Locke appeals to a relativity shown by the ideas of secondary qualities, not had by those of primary qualities. No matter what the conditions under which I perceive a body, my idea of it always includes extension. But the perception of bodies can yield, under some conditions, an idea of heat, and under others, an idea of cold. Worse, at a distance from a fire, I have an idea of warmth, which is replaced by an idea of pain when I mistakenly place my hand in the fire.

I have skipped various peripheral material to turn to the idea of power, one of the most important of all. I have already noted that his idea includes that of the ability to bring about change (active power) and to suffer it (passive power).

Locke claimed that experience shows that the mind has the active powers of beginning or ceasing its own operations and of initiating or inhibiting motion in the body. This power is activated by a preference. He claims that if a mind can, merely on the occasion of a preference, affect the operations of the mind or the motion of the body, that mind is free to do so. If it cannot, it is necessitated to do something else.

Suppose we call the preference for a state of affairs the motive. My motive for typing these notes is my preference for my students to suttee them. I need not do so; I am free to go play golf instead. Locke says that my preferences are determined by the pleasure or pain I project as the result of the contemplated act. But then it seems as if my actions are determined by what is pleasurable for me and what is painful for me. Locke' response is that the situation is more complicated than it would seem. I am at liberty to ignore, say, an intense, immediate pleasure because I understand that it would in the long term produce more pain. So ultimately, it is our ability to reason about pleasures and pains which constitutes the foundation of our freedom.

Locke' view of human liberty is directed forward in time. It does not matter how one gets to the point of choice, so long as the mind is able bring about the desired event, the act is free. Many people find this kind of freedom to be of small comfort. They think that how one' preferences are determined is the key to liberty. If my preferences are determined by pleasure and pain alone, then I am no better than a robot with no control over my destiny.

The next topic of interest is that of substance. Given his starting point, Locke is able to pronounce that in many cases we observe certain ideas to go together constantly. A certain bulk, shape, array of colors, speech patterns, etc., go together so constantly that we give them one name, say Bill Clinton. Calling this collection of ideas by a single name need not have any significance beyond the mere co-existence of the qualities, as Berkeley pointed out. But Locke made the further claim that the co-existence can only be understood if there is something which is the reason for their co-existing in just that way. Call this the "support" or "substratum." Then our idea of a substance in general is that of co-existing qualities supported by something.

Of course, it would help the explanation if Locke could go beyond mere metaphor. The word 'support' cannot be taken literally (again as pointed out by Berkeley), since it then would be just another observable thing, like the foundation of a building. But there is nothing more to be said. Locke says that we are in the position of children, who can only say "something" when asked what is responsible for an event. Or, we are like the philosophers of India who, when asked about the support of the world, say that it rests on an elephant, and when asked further what supports the elephant, say that it rests on the broad back of a turtle. Finally, when asked what supports the turtle, he says, "something, I know not what." Suffice it to say that Locke's doctrine of substance was a weak point in his system.

The same story goes for mental substance. Our minds contain ideas and operations upon them. But the spirit which is responsible for these ideas and operations is also an unknown something. Thus although we know what spirit does, we do not know what it is. This leads to skepticism about whether the spiritual substance is absolutely immaterial. Bishop Stillingfleet, in particular, attacked Locke for leaving open the possibility that matter thinks.

The skepticism about mental substance spills over into the issue of identity over time. Could the same spirit be connected to different bodies or different personalities? Locke claimed that the criterion of identity over time is the same beginning. A rock is formed out of molten lava. Its existence begins at that time and it continues until the rock is broken. So long as there is continuity from the beginning, it is the same rock. The breaking constitutes a new beginning for each of the fragments.

The most simple case of identity is that of identity of mass. A mass is the same when all the particles making it up are the same. Substitute one for another, and it is a different mass. This notion of the same mass is not very useful, however, since very few masses in the universe are so stable that they are not adding or losing parts, and hence becoming new masses.

A more complicated case of identity is that of a vegetable. We acknowledge that vegetables need not have exactly the same particles in order to be the same. What is the same, rather, is the dispositions and organization of the thing, which Locke seems to identify with its life. A tree sheds its leaves and grows new ones, all the while remaining the same tree. By extension (and with an extended use of 'life') we can say that a machine is re-identified by its dispositions and organization. Animals are too, the only difference being that they are self-moving. Insofar as a man is an animal, a man is subject to the same-life identity condition.

Given this condition, it seems that Locke can solve the old problem of the identity of a ship which is wholly rebuilt. In its original location, a part of the ship is removed to another place, then replaced by a new part. An adjoining part is removed and transported, attached to the first removed part, and replaced. Eventually, there is a ship in the original place which has all new parts. It seems to be the same ship as the original, by Locke' criterion. (Compare the claim that all the cells in the human body are replaced in ten years.)

We move now to Book IV of the Essay, wherein Locke presents his theory of knowledge. The material discussed in the lecture is tied to the handout distributed in class. The handout provides a matrix. The content of the cells is the extent of what is known for fifteen classifications of knowledge ((4 x 4) - 1, due to a consolidation of two classifications).

One dimension of the matrix is the degree of knowledge. Actually, the lowest degree of "knowledge" is not knowledge at all, but mere opinion. The lowest degree of knowledge proper is sensitive knowledge, which is based on sense experience rather than merely on ideas. Knowledge not based on sense experience is intuitive (in which ideas are compared directly with each other) and demonstrative (in which they are compared indirectly, via intermediary ideas). The presence of intermediaries in demonstrative knowledge introduces an element of slight uncertainty not present with intuitive knowledge.

The second dimension is the objects of knowledge and opinion. Identity and diversity is the simplest sort: two ideas are known to be (qualitatively) identical or different from each other. Black is not white and white is white, etc. All are known intuitively. Relations among abstract ideas are all known either intuitively or demonstratively, if they are known at all (mathematical speculation is a matter of opinion). Since they are abstract, knowledge about them is not sensitive.

Co-existence and connection are relations that hold of real objects, as opposed to abstract ideas. I have combined the categories of the intuitive and demonstrative here, since Locke has little to say about them. Few relations of co-existence are known through the examination of ideas alone. Of greater importance are relations discovered to hold in sense objects. Most of them are subjects of opinion, and only those which are actually present in perception are known sensitively. Thus I may know that my yellow watch is gold.

Knowledge of existence is somewhat artificially divided among the various degrees. I know myself through the direct inspection of ideas. There is a demonstration of God' existence, and there is sensitive knowledge of objects actually present to my senses. Thus I do not know that the classroom in which the lectures are given exists at the very moment I am typing these notes in my office. So in truth, we know very little sensitively, since what we perceive at any time is very limited.

Locke painted himself into a corner in his description of knowledge as concerned only with ideas. Paradigm examples of knowledge, on this view, are that white is not black, and that the sum of the squares of the sides of a right triangle is the square of the hypotenuse. But both are independent of any facts except those concerning ideas themselves. Locke, rightly, asks why on his account of knowledge anything which comes into anyone' head does not count as knowledge.

He notes that we intend for some of our ideas to refer beyond themselves to an external reality, and that the title of knowledge must be reserved for those ideas which correspond to it. But this raises the problem of the criterion for distinguishing which ideas conform to reality and which do not. Rather than giving a general criterion of knowledge, Locke proceeds on a case-by-case basis.

The second case he considers is the least interesting. We have seen already that mathematical knowledge is supposed to be based on intuition and demonstration concerning abstract ideas. Locke adds that they are representative of themselves, and the question of external reality touches them only indirectly. If there are things that correspond to our abstract ideas, then demonstrations about them apply to those things. The same goes for other kinds of abstract ideas, including moral ideas.

The first case of correspondence is that of simple ideas to their originals. Locke assumed that these ideas are not made up by ourselves (we can only operate on given simple ideas), they correspond to what causes them. Note, however, that Locke has not yet shown that we have knowledge of the existence of other things. It still remains open whether the source of these ideas is an external reality, and the nature of the correspondence has not been established.

The third case is the least ambitious. This concerns complex ideas of substances. To what extent does my idea of a raspberry correspond to the thing? Locke provisionally answers that the correspondence is rough.

Finally we turn to the question of our knowledge of the existence of things. That we know our own existence intuitively is based on appeal to the argument of Augustine and Descartes, that doubting one' own existence presupposes the existence of a doubter, and hence is futile. This knowledge is intuitive, it seems, because one can hold this thought in its entirety at a single time.

The proof of the existence of God is problematic. As a good empiricist, Locke gave a proof a posteriori, or from experience. The starting point is the already-demonstrated existence of himself. From this narrow basis he moves outward using a version of the principle of sufficient reason (itself never justified), that nothing cannot produce anything. To avoid a regress of producers, he claims that we must acknowledge that from eternity there has been something. (It is not clear why he could not appeal instead to a first cause which was not produced, rather than produced by nothing).

Next he claimed that this something is most powerful. This conclusion is quite dubious on the grounds that the only thing he need account for is the existence of himself. But even if he did invoke this being as the cause of the existence of the world, the being need only be as powerful as it takes to produce the world as its effect.

Finally, this eternal, most powerful, being is said to be most knowing. Locke has noted that he himself is an existing thinking thing, and now claims that thinking cannot arise spontaneously from matter. Only a thinking thing could give rise to a thinking thing. Further, the being is most knowing. But the same problem as before arises here: the being need only be powerful enough to produce the level of thinking found in the world. In general, proofs a posteriori have the problem that the infinite properties of a God seem to surpass what is required to explain the world around us.

Having given a flawed argument for the existence of God, Locke moved to give a shaky account of our knowledge of the existence of other things. This knowledge is sensitive, and is very limited in its scope. One can know of the existence only of those things with which one is in sensory contact.

Locke' theory of sensitive knowledge is very much like some contemporary theories of knowledge. It has two components, one ˘external÷ and the other ˘internal.÷ The external component in knowledge is that a causal relation between the knower and the object is a necessary condition for knowledge. ˘It is therefore the actual receiving of ideas from without that gives us notice of the existence of other things, and makes us know, that something doth exist at that time without us, which causes that idea in us; though perhaps we neither know nor consider how it does it÷ (IV,XI,2). Although this external connection is necessary for knowledge, however, it is not sufficient.

The second ingredient is what is Ernest Sosa calls an "epistemic perspective," or an assessment of the way our faculties operate to produce the ideas in us. The eyes are said to give ˘testimony÷ in which we have confidence. "If we persuade ourselves that our faculties act and inform us right concerning the existence of those objects that affect them, it cannot pass for an ill-grounded confidence" (IV,XI,3). One thing he said in this connection caught the eye of Berkeley, that we cannot doubt the existence of the things we see and feel. But what, Berkeley asked, do we see and feel other than the ideas themselves?

Locke says that he "has reason to rely" on the testimony of the senses. He argues that has the assurance of God. It appears from IV,XI,3, that he thinks that since God has given him these faculties, and they are correlated with the production of pleasure and pain ("one great concernment of my present state"), he can be confident in the testimony of the senses. This is reminiscent of Descartes' claim that God would be a deceiver had he been created with faculties whose manifest testimony is erroneous.

Locke then gives four concurrent reasons to be confident in the testimony of the senses (or equivalently, to support his "epistemic perspective.") The first is that we cannot invent specific kinds of ideas, say the taste of a pineapple, so that they require "exterior causes." Locke can cite only empirical evidence for this conclusion, i.e., that "nobody" gets the taste of a pineapple until they actually bite into one. It is not clear that this establishes the impossibility of so doing, however. But even if the empirical evidence Locke cites is sufficient for his purposes, note the weakness of the conclusion. Locke cannot say what the exterior cause is. As Berkeley noted, the exterior cause might be God.

The second reason is also vulnerable to the same objections. Locke claims that the production of some ideas seems to be forced on me. I have no control over them (the come ˘willy-nilly÷ into the mind), and so they are the product of an exterior cause. As with the first case, Locke cites empirical evidence which may or may not be sufficient for his conclusion. And he again is vulnerable to Berkeley's criticism that the specific exterior cause is not established by the argument.

The fourth reason (which is more continuous with the first two than is the third), is that the senses bear testimony to one another. This is a sound principle for evaluating testimony when there is some other evidence, but it does not work well in the present case. If a number of witnesses giving testimony are systematically lying or systematically deluded, then the coherence of their testimony is of no value. The only conclusion Locke could draw is that whatever the exterior cause of sensitive ideas may be, it is likely to be the same for all the sense modalities. Coherence may well be a criterion separating the dreamed or imagined from some other ideas to be called "real," but the nature of the real is unknown, at least on the basis of these three arguments.

The third reason is an apparent difference between ideas, in that the pleasure or pain associated with some is dramatically more intense than what is associated with ideas of imagination, dreams, etc. This argument is not very strong, since hallucinations can bring on great pain, as with Delayed Stress Syndrome

. Locke went on to delimit the extent of our knowledge to objects actually affecting the senses, as is implied by his externalist condition discussed above. (I did not mention in lecture that this condition allows knowledge on the basis of memory of actually sensed objects, since the ideas were caused originally in the appropriate way.) On the other hand, we cannot know that other minds exist, though it is highly probable that they do. The required external causation falls short. We are not affected by the minds of others, but only by physical phenomena: what we see, hear, feel bodies to do.

This introduces the topic of the use of reason in matters that fall short of knowledge. Locke's general principle is that we ought to assent to a proposition when the preponderance of evidence is on its side, i.e., when it is highly probable. On the other hand, it is not always the case that we ought to withhold assent when there is not a preponderance of evidence. This loophole exists because there are some matters which are ˘above reason,÷ in the sense that there is no way to adduce empirical evidence for or against. These cases allow for consent on the basis of faith.

On the other hand, there are cases in which there is an absolute preponderance of evidence against a proposition, when it is "contrary to reason." I may not give my assent to what conflicts with what I know to be true.

What is wrong with assenting to a proposition (e.g., that there is more than one God) that is contrary to reason? It is an abuse of the faculty of reason which God gave us. Thus, Locke held that the true God would never give us faculties which we are supposed to subvert in order to know God. If we may revert to Descartes once again, God would be a deceiver if such a condition holds.

Locke' religious convictions were rationalistic. That is, he thought that religious belief has a rational basis. We have already seen that he tried to demonstrate from rational principles the existence of God. He also held that revealed religion can be considered testimony which has its own evidential weight.

There are two sorts of revelation possible: direct implantation of ideas in our minds by God, and public signs such as the content of scripture. In both cases, whether we should place confidence in these sources depends on whether they have good credentials, i.e., whether we have good reason to think that they are actually the word of God.

Here Locke began his attack on enthusiasm, which would set up revelation without reason. Locke states that this is impossible, so that anyone professing to do this must be stating his own fancies. The mark of the enthusiast is the justification of the belief by the mere degree to which it is believed. Locke diagnosed the syndrome as the product of an overheated brain.

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