Hello everybody! In this lecture we will be discussing a bit of Locke’s empiricism, including a discussion of his understanding of Primary and Secondary qualities. If you remember from last time, Rationalism is the view that, at least within a domain or subject matter, a priori reason is the only source of knowledge. “A priori” means before the senses. Empiricism denies this. Instead, empiricists claim that the senses are the source of knowledge. As opposed to a priori we call this a posteriori—after the senses. As we mentioned before, the categories of rationalism and empiricism are not necessarily held in an all-or-none fashion by philosophers. While one cannot be both an empiricist and a rationalist regarding the same domain or subject matter, one can be an empiricist regarding some subject matter and a rationalist regarding others. Descartes is a prime example of a rationalism and Locke of empiricism. When philosophers are categorized in this way, it tells you whether they believe that it is pure reasons or the senses are the most important source of knowledge, even though their views might have subtlety and nuance. Since Descartes and Locke are paradigm cases of rationalism and empiricism, their views are fairly pure. We are about ready to start digging into Locke, but, before we do, we should say what he means by an “idea.” For Locke and Idea is: "whatsover is the Object of the Understanding when a Man thinks." [Essay I i 8] While an idea can be anything a person thinks of, including abstract concepts, a simple idea can only come through sensory experience. Simple ideas are our direct, primitive, sensory experiences. Simple ideas are important because they are required for all other ideas. All other ideas are built in some way from simple ideas. Since simple ideas can only come from the senses, this means that reasoning relating to abstract concepts, including truths of math and logic, all depend on the senses. Therefore, for Locke, all ideas, and as a result all knowledge, comes from experience. You may have heard the term “blank slate” or “tabula rasa” before. Locke is talking about mind and thought, so this is in many ways a psychological theory. He believed that we are all born empty of ideas. These ideas are then marked or impressed upon us through our senses. He denied the notion of innate ideas. A useful analogy would be that the senses impose ideas upon us like chalk scratched on a chalkboard or objects making impressions on a soft piece of wax. A more modern analogy would be an unformatted hard drive. As we will see Locke’s ideas are quite scientific and in many ways modern views reflect his own, although even the most empiricist of neurologists now know that our brains have specific ways in which they format and process the information they receive. A good example would be how our brains flip the images we. As some of you may know from the way cameras work, the image that is reflected on our retina is inverted. Our brains, however, correct this image for us. What’s more, if people wear glasses that make them see the world upside down, after several weeks of trying to process this information, their brains will correct this image for them again. Then, if they take off the glasses, it will take a while for them to see the world right-side up again. Steven Pinker has a noteworthy quote: “The mind cannot be a blank slate, because blank slates don’t do anything… The inscriptions (on such a slate) will sit there forever unless something notices patterns in them, combines them with patterns learned at other times, uses the combinations to scribble new thoughts onto the slate, and reads the results to guide behavior toward goals.“ Of course, the brain being born equipped to process information in a particular way is not quite the same thing as having a concept or idea. A computer processor processes information in a particular way, but the useful structures that it forms as a result later sit in ram. Modern psychologists and neurologists do have some disagreement about the extent to which we are dependent upon learning and sensation within a reasonable range. That said, let’s start digging into Locke. We are reading the section of Chapter VIII called “Some Farther Considerations Concerning Our Simple Ideas.” Simple ideas: Locke notes that whatever causes a perception in us also produces a simple idea in us. In other words, all of our immediate sensations and perceptions are ideas when we are aware of them. He also notes that, interestingly, these positive ideas can be caused by the absence of a thing as well as the presence of it. For example a shadow is the absence of light entering our eyes, or silence is the absence of noise. Yet both shadow and silence produce ideas in us. This is what he means when he says that a deprivation of the cause of a sense can produce positive ideas in us. For example, imagine that your are watching a music video on YouTube. If there were a blackout your eyes might be deprived of light, but this causes a new idea in you, just as the deprivation of sound causes another idea. Darkness and silence respectively. Locke says that this is probably because all sensation and perception is caused by difference degrees and modes of motion in our animal spirits. This he says, “The abatement of any former motion must as necessarily produce a new sensation as the variation of increase of it.” So, though these sensations are caused by being deprived of a stimulus, they still generate real ideas, and thus Locke says that it makes perfect sense to say that one sees darkness, feels a drop in temperature, or hears silence. If this sounds odd then think of a hole—maybe a hole in a shirt or a hole in a piece of Swiss cheese. Were you able to picture one? Of course you were. We have a positive idea of what a hole is, even though it is the absence of a thing. It makes perfect sense to say that you see a hole in a wall, even if that hole leads into an utterly dark cave, in spite the hole itself providing an absence of stimulation to your eyes. While doing the reading you might have been thrown by his use of the phrase “animal spirits.” Not understanding the context, this term is a bit misleading. Locke was writing before a modern understanding of neurology. He is not imaging little tigers and foxes running through your system. This refers to how impulses travel through the body, carrying information, and causing movement and memories. It was then thought perhaps to be a system of fluids in the body that affect sensation and memory. That there is no such fluid as “animal spirits” does not make Locke’s ideas irrelevant, and would simply be substitution for a motion of electro-chemical reactions inside the body and through our neurons. “Animal Spirits” basically filled the explanatory role that our modern understanding of nerves does now. The key idea is that simple ideas are delivered to us though a kind of motion carried through the body resulting in senses. In terms of how the senses work, whether it is the motions of elections or a mysterious fluid, this is essentially correct. Next Locke makes a very important distinction that was not at all obvious to the people in the 17th century. He points out that there is a difference between the ideas in the mind and the qualities that are in bodies or objects themselves. Think about how he just described perception. Perception is ultimately conveyed to us though motion---and, as we mentioned, according to our modern scientific understanding this is correct, though we have replace the notion of animal spirits with a more sophisticated understanding of biology. This means that our minds are never perceiving the objects themselves when we perceive them. Instead, we can at best perceive the world indirectly through the sensations our brains conjure through the motions sent through our nerves. It is important to appreciate what a modern view this is, and keep in mind this structure, because this will be key to understanding the difference between primary and secondary qualities. Now back to our definitions. Remember that ideas are that which the mind perceives. Locke notes that ideas in the mind are not the same thing as qualities in a body. * Ideas can be whatever concept or sensation you are immediately aware of, including complex or abstract ideas built from simple ideas. * Simple ideas are the primitive ideas produced in us directly by sensation. A quality, on the other hand, is the power of a thing to produce an idea in us. Example: A snowball has the power to produce the ideas of roundness, white, and cold in us via its qualities of roundness, whiteness, and coldness. There are two kind of qualities, and this is a major part of Locke’s theory. Primary qualities: These are qualities that cannot be separated from an object. They are really part of any object, so to speak. * All matter which can be perceived has such qualities, and it is through the primary qualities that they produce sensations in us. Secondary qualities: These are qualities that do not exist in the object itself. Instead an object has the ability to produce these ideas in us through the motion and impulse of its primary qualities. Secondary qualities exist only in the mind of the perceiver and do not resemble the object itself. Locke uses the example of a piece of grain. If you were to take a grain of wheat and cut it in half, it still has certain qualities. Indeed, no matter how many times you divide it, it will have these qualities. These qualities are: * Extension. The form it fills in space. * Solidity. * Mobility or motion. * And number. Even if you were to cut it up into imperceptibly small pieces those pieces would still have these qualities. Secondary qualities, on the other hand, only exist in our minds, but they are produced by the primary qualities. Examples of these are color, sound, taste and smell, as well feeling heat and cold from an object and so forth. * These things will vary in us. * For example, water of the same temperature might sometimes feel warm or sometimes feel cold, depending upon the current temperature of your hand. * Food might taste differently when you are sick or depending upon your state, such as drinking orange juice after brushing your teeth. * Color will vary depending on the light, and a person’s eyes. * We know now that even what surrounds objects can cause us to see them in differently. Here is a quick proof via an optical illusion. The blocks labeled A and B appear to be different colors. This is because of their context. As you can see when we fade away all the other parts of the picture, they are really the same shade. If I bring back the image, they appear to be different colors again. It is through the primary qualities that all objects possess that they are able to cause our minds to perceive secondary qualities—Locke says that they do this through impulse or motion. The ability of objects to affect each other, such as fire to melt wax, is also the result of its primary qualities. Now for some arguments and implications. Since external objects are not themselves part of our minds—that is to say that they are external to us---Locke argues that in order to cause a perception in us that some impulse must travel through us—through our nerves, or in the view of the day, animal spirits, and cause this sensation in us. Visual qualities can be observed at a distance. Therefore Locke theories that some sort small particles must be traveling from the object to our eyes. Note how modern this view is. Locke didn’t know about photons, but he is hypothesizing something very much like them when he talks about imperceptible particles entering the eyes. Primary qualities are really part of the object and resemble the object in some way. Second qualities do not resemble the object. Again, this is a very modern view. Photons do not have any color. They produce the sensation of color in us by stimulating different cones in our eyes depending upon the frequency of their wavelengths. Particles of cooking food do not smell like anything themselves---they have a particular scent to us because of the receptors they stimulate in our nose. As for sound, vibrations are just vibrations—they produce a sound in us through motions imparted to the eardrum and carried through our nerves to our brains. Locke here is arguing against what was a commonly held view at the time—that of naïve realism. This is the belief that these qualities that Locke identifies as secondary qualities are actually part of the object. That an apples objectively appears to be red and objectively tastes sweet independent of any observers. We now know this not to be the case. Locke’s theory explains why sensations can vary in us with circumstance. The theory of the sensation of heat being produced in us by motion of particles explains why a fire is hot close up but only warm at a distance. Have you ever heard of the fruit called miracle berries? When I cover this topic in my live courses I would often buy some miracle berry pills to distribute to the students. When you let one of these dissolve on your tongue, even lemons will taste very sweet—almost sickly sweet, like syrupy lemonade. But shape, figure/extension, number, and motion exist independently of us. These are therefore real qualities. He says, “Take away the sensation of them; let not the eyes see light or colors, nor the ears hear sounds; the palate not taste, or the nose smell, and all colors, tastes, odors and sounds as they are such particular ides vanish and cease and are reduced to their causes----bulk, figure, and motion of parts.” Of course we might note that the shape of objects seems to change with distance and angle, but many of these are confirmed by multiple senses and can be measured. Hold a pencil close to your eyes and then away from your eyes and it will change size. Tilt it and it will appear to be of a different shape. Nevertheless, it will feel the same in your hand. Measure it against a ruler, move it further away from you, or have somebody else measure it, and it will retain the same size. Other philosophers, however, question whether secondary qualities are more certain than primary qualities. Hume, for example, another empiricist, questions the certainty of such qualities. So, that pretty much sums up the section of reading that you did for Locke, but it is important to put it into context. What we have presented here is an important part of Locke’s epistemology. Locke is telling us: 1. How we get ideas in the first place. 2. Which qualities we can trust as being within the objects themselves. 3. And which qualities are produced in us by primary qualities interacting with our minds. His theory is also that we essentially start off as blank slates or tabula rasa, and we gain ideas as they become presented to us through the senses. Simple ideas can be built up into more complex ideas. So, for Locke, the empiricist, senses are fundamental to knowledge---we cannot gain ideas at all except through the senses. This, of course, is only a brief overview of Locke’s theory. He goes into detail about how we develop certain kinds of ideas about what he calls modes, relations, and substances, and develops his theory in much more detail in his famous Essay Concerning Human Understanding. What we discussed were the basics. And, that about wraps it up for this lecture. Until next time…