An Essay Concerning Human Understanding John Locke §1 Since it is the understanding that sets man above all other animals and enables him to use and dominate them, it is certainly worth our while to enquire into it. The understanding is like the eye in this respect: it makes us see and perceive all other things but doesn’t look in on itself. I. 1. §2 I shan’t involve myself with the biological aspects of the mind. For example, I shan’t wrestle with the question of what alterations of our bodies lead to our having sensation through our sense-organs or to our having any ideas in our understandings. Challenging and entertaining as these questions may be, I shall by-pass them because they aren’t relevant to my project. All we need for my purposes is to consider the human ability to think … Someone observing human opinions from the outside—seeing how they conflict with one another, and yet how fondly they are embraced and how stubbornly they are maintained—might have reason to suspect that either there isn’t any such thing as truth or that mankind isn’t equipped to come to know it. I. 1. §3 So it will be worth our while to find where the line falls between opinion and knowledge, and to learn more about the ‘opinion’ side of the line. What I want to know is this: When we are concerned with something about which we have no certain knowledge, what rules or standards should guide how confident we allow ourselves to be that our opinions are right? Here is the method I shall follow in trying to answer that question. First, I shall enquire into the origin of those ideas or notions—call them what you will—that a man observes and is conscious of having in his mind. How does the understanding come to be equipped with them? Secondly, I shall try to show what knowledge the understanding has by means of those ideas—how much of it there is, how secure it is, and how self-evident it is. I shall also enquire a little into the nature and grounds of faith or opinion—that is, acceptance of something as true when we don’t know for certain that it is true. I. 1. §4 I hope that this enquiry into the nature of the understanding will enable me to discover what its powers are—how far they reach, what things they are adequate to deal with, and where they fail us. If I succeed, that may have the effect of persuading the busy mind of man •to be more cautious in meddling with things that are beyond its powers to understand; •to stop when it is at the extreme end of its tether; and •to be peacefully reconciled to ignorance of things that turn out to be beyond the reach of our capacities. §6 It is very useful for the sailor to know how long his line is, even though it is too short to fathom all the depths of the ocean. I.I. §8 Before moving on, I must here at the outset ask you to excuse how frequently you will find me using the word ‘idea’ in this book. It seems to be the best word to stand for whatever is the object of the understanding when a man thinks; I have used it to express whatever is meant by ‘phantasm’, ‘notion’, ‘species’, or whatever it is that the mind can be employed about in thinking; and I couldn’t avoid frequently using it. Nobody, I presume, will deny that there are such ideas in men’s minds; everyone is conscious of them in himself, and men’s words and actions will satisfy him that they are in others. First, then: How do they come into the mind? I. 2, §4 Children and idiots have no thought—not an inkling—of these principles [e.g. It is impossible for the same thing to be and not to be], and that fact alone is enough to destroy the universal assent that any truth that was genuinely innate would have to have. For it seems to me nearly a contradiction to say that there are truths imprinted on the soul that it doesn’t perceive or understand—because if ‘imprinting’ means anything it means making something be perceived: to imprint anything on the mind without the mind’s perceiving it seems to me hardly intelligible. So if children and idiots have souls, minds, with those principles imprinted on them, they can’t help perceiving them and assenting to them … It may be said that a proposition that the mind has never consciously known may be ‘in the mind’ in the sense that the mind is capable of knowing it; but in that sense every true proposition that the mind is capable of ever assenting to may be said to be ‘in the mind’ and to be imprinted! Why, according to Locke, is Nativism [belief in innate ideas] not only unnecessary but illegitimate? One prominent theme is that if there were innate principles in the mind—his example is Whatsoever is, is—we would be aware of them, and they would therefore be universally assented to. But, he argues, children and idiots cannot even make sense of such claims, let alone assent to them. He goes on to argue that various fallback positions—assent when they understand, assent when they begin to reason, capacity to assent under appropriate conditions—all reduce the claim to a sort of triviality. The upshot is that innateness is either a real alternative to Empiricism but obviously false, or trivially true but not incompatible with Empiricism. http://plato.stanford.edu/entries/innateness-history/#EmpAttNatLocHum Underlying much of Locke's attack is the Cartesian view that to claim something is ‘in the mind’, innately or not, is to give it a place in our conscious awareness. Leibniz's bold hypothesis of non-conscious mental states would, if successful, sweep aside most of Locke's arguments against innateness. But we need to keep in mind that the polemics in the Essay, though they were historically influential, are almost a sideshow. The real issue is whether the Empiricist can construct a satisfactory account of human knowledge without adverting to any innate ideas and principles. To meet this challenge, Locke (and to an even greater extent Hume) offered what may be termed adequacy of the stimulus counterarguments. II.1.6 Everyone is conscious to himself that he thinks; and when thinking is going on, the mind is engaged with ideas that it contains. So it’s past doubt that men have in their minds various ideas, such as are those expressed by the words ‘whiteness’, ‘hardness’, ‘sweetness’, ‘thinking’, ‘motion’, ‘man’, ‘elephant’, ‘army’, ‘drunkenness’, and others. The first question, then, is How does he acquire these ideas? It is widely believed that men have ideas stamped upon their minds in their very first being. My opposition to this in Book I will probably be received more favourably when I have shown where the understanding can get all its ideas from—an account that I contend will be supported by everyone’s own observation and experience. II.1.§ Let us then suppose the mind to have no ideas in it, to be like white paper with nothing written on it. How then does it come to be written on? From where does it get that vast store which the busy and boundless imagination of man has painted on it—all the materials of reason and knowledge? To this I answer, in one word, from experience. II.16.§1 Among all the ideas that we have, none is •suggested to the mind by more ways, and none is •more simple, than the idea of unity or one. It •hasn’t a trace of variety or composition in it; and •every object that our senses are brought to bear on, every idea in our understandings, every thought of our minds, brings this idea along with it. This makes it the most intimate to our thoughts, and also the most universally applicable idea that we have. For number applies itself to men, angels, actions, thoughts, everything that exists or can be imagined … §5 By repeating the idea of a unit, joining it to another unit, we make one collective idea marked by the name ‘two’. If someone can do this, and can carry the procedure further by adding one to each collective idea that he reaches, and also gives a name to every number whose idea he comes to, then he can count. 1. If you want to know what kind of idea it is that we name ‘infinity’, you can’t do better than to consider •what the idea of infinity is most immediately applied to by the mind, and then •how the mind comes to form this idea. Finite and infinite seem to me to be viewed by the mind as modes of quantity, and to be attributed primarily and initially only to things that have parts, and can be augmented or diminished by the addition or subtraction of parts, however small. §3 Someone who has an idea of some stated length of space finds that he can repeat it, going from the idea of one foot (say) to that of two feet, and that by further addition he can go to three feet, and so on without ever reaching an end of his addition. This holds good whether he started with the idea of a foot, or of a mile, or of the diameter of the earth. Whatever he starts with, and however often he multiplies it, he finds that however far he has gone he has no more reason to stop— and isn’t one jot nearer the end—than he was when he set out. From this he takes the idea of infinite space. §4. That account of the source of the idea of infinite space doesn’t settle whether there actually exists a boundless space answering to the idea, because our ideas aren’t always proofs of the existence of things. II.20.§6 Among the simple ideas that we receive from both sensation and reflection, pain and pleasure are two very considerable ones. •Bodily sensations may occur alone or accompanied by pain or pleasure; and •the thoughts or perceptions of the mind may also occur solo or else accompanied by pleasure or pain, delight or trouble, call it what you will. Like other simple ideas, these two can’t be described, nor can their names be defined; the only way to know them is by experience. A ‘definition’ of them in terms of the presence of good or evil makes them known to us only by making us reflect on what we feel in ourselves when we think about or undergo various operations of good and evil. Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily reflection is occupied with them: the starry heaven above me and the moral law within me. Neither of them need I seek and merely suspect as if shrouded in obscurity or rapture beyond my own horizon; I see them before me and connect them immediately with my existence. - Immanuel Kant, Critique of Practical Reason Fish can distinguish between larger and smaller quantities, with an additional ability to "count" up to three, according to research on tropical angelfish. Angelfish are regarded as being one of the world's most intelligent fish, but scientists believe other fish species also possess the math-related skills outlined in a new Animal Cognition paper. Doing something akin to counting up to three might sound underwhelming, but math itself is a very human-centric concept that may need reconsideration if comparisons are to be made with the abilities of non-human species. "We all think we know what we mean by 'counting,' but do we really?" asked coauthor Robert Gerlai. "Is recounting a series of 1 to 100 counting? Is 2+3=5 counting? Is calculating the square root of a number counting, or perhaps is the mathematics necessary for quantum physics counting?” http://news.discovery.com/animals/angelfish-counting-math-110109.html "The point is that even within our own species, mathematical abilities vary tremendously," Gerlai, a University of Toronto Mississauga professor of psychology, told Discovery News. "So far, most biological, including behavioral, traits we initially believed to be unique properties of our own species have turned out to have some homologues in animals.” Gerlai and Luis Gomez-Laplaza of the University of Oviedo in Spain exploited the previously determined tendency of angelfish to seek protection in unfamiliar environments by joining the largest possible fish group, called a shoal. To rule out possible confounding effects arising from sexual interactions, the researchers only used juvenile angelfish for their experiments. Test fish placed in special compartmentalized tanks were given a simultaneous choice between shoals containing different numbers of fish. The angelfish were always able to select the larger of two groups so long as the ratio between the shoals was 2:1 or above. Below that ratio, their choices were less predictable, suggesting a limit to their quantity estimation abilities. After the findings were published, the researchers, according to Gerlai, "have already collected new data suggesting that angelfish can discriminate much more precisely than this. That is, angelfish can tell the difference between 3 and 2, for example." He added, "This ability does resemble 'counting' individual items as opposed to estimating quantities, but this counting ability does not extend beyond three." To make our difficulties plain, let us concentrate attention on the table. To the eye it is oblong, brown and shiny, to the touch it is smooth and cool and hard; when I tap it, it gives out a wooden sound. Any one else who sees and feels and hears the table will agree with this description, so that it might seem as if no difficulty would arise; but as soon as we try to be more precise our troubles begin. Although I believe that the table is ‘really’ of the same colour all over, the parts that reflect the light look much brighter than the other parts, and some parts look white because of reflected light. I know that, if I move, the parts that reflect the light will be different, so that the apparent distribution of colours on the table will change. It follows that if several people are looking at the table at the same moment, no two of them will see exactly the same distribution of colours, because no two can see it from exactly the same point of view, and any change in the point of view makes some change in the way the light is reflected. – Russell, The Problems of Philosophy For most practical purposes these differences are unimportant, but to the painter they are all-important: the painter has to unlearn the habit of thinking that things seem to have the colour which common sense says they ‘really’ have, and to learn the habit of seeing things as they appear. Here we have already the beginning of one of the distinctions that cause most trouble in philosophy – the distinction between ‘appearance’ and ‘reality’, between what things seem to be and what they are. The painter wants to know what things seem to be, the practical man and the philosopher want to know what they are; but the philosopher’s wish to know this is stronger than the practical man’s, and is more troubled by knowledge as to the difficulties of answering the question.” They [the experimental subjects] watched two separate sets of Hollywood movie trailers, while fMRI was used to measure blood flow through the visual cortex, the part of the brain that processes visual information. On the computer, the brain was divided into small, three-dimensional cubes known as volumetric pixels, or “voxels.” “We built a model for each voxel that describes how shape and motion information in the movie is mapped into brain activity,” Nishimoto said. The brain activity recorded while subjects viewed the first set of clips was fed into a computer program that learned, second by second, to associate visual patterns in the movie with the corresponding brain activity. Brain activity evoked by the second set of clips was used to test the movie reconstruction algorithm. This was done by feeding 18 million seconds of random YouTube videos into the computer program so that it could predict the brain activity that each film clip would most likely evoke in each subject. Finally, the 100 clips that the computer program decided were most similar to the clip that the subject had probably seen were merged to produce a blurry yet continuous reconstruction of the original movie. Reconstructing movies using brain scans has been challenging because the blood flow signals measured using fMRI change much more slowly than the neural signals that encode dynamic information in movies, researchers said. For this reason, most previous attempts to decode brain activity have focused on static images. “We addressed this problem by developing a two-stage model that separately describes the underlying neural population and blood flow signals,” Nishimoto said. Ultimately, Nishimoto said, scientists need to understand how the brain processes dynamic visual events that we experience in everyday life. “We need to know how the brain works in naturalistic conditions,” he said. “For that, we need to first understand how the brain works while we are watching movies.” http://newscenter.berkeley.edu/2011/09/22/brain-movies/