So, put concisely, consciousness
has to do with two things:
Modern Western philosophy began with an inquiry into consciousness. For our purposes, the chief figure in this event is Rene Descartes (1596-1650), a French philosopher who is generally regarded as the "father" of modern philosophy.
Before Descartes, in ancient and medieval times, philosophy was based largely on arguments from authority -- whether that authority was Plato or Aristotle, or the Bible and Church Fathers. Plato himself believed that knowledge began with eternal truths, known without benefit of empirical evidence. What became known as scholastic philosophy, as taught by Peter Abelard, Albertus Magnus, Thomas Aquinas, and others during the Medieval era sought to combine the Church's revelations with the natural reason of Aristotle. All this began to change during the Renaissance of the 15th and 16th centuries, and especially in the 16th and 17th centuries, when a new line of philosophy began to emerge, based on the principles of scientific method articulated by Francis Bacon (1561-1626) well as the exercise of reason -- which is where Descartes comes in.
In a kind of "origin myth", Descartes wrote that a dream he had on the night of November 10, 1619 convinced him that "True knowledge comes from human reason alone". Accordingly, Descartes adopted a stance of methodical doubt, but doubt without skepticism. He rejected everything he had been taught in church and school while retaining the assumption that there are some truths that can be known through reason. In this way, he sought to erect a complete system of knowledge based solely on rational argument. By the way: by adopting this rationalist view of knowledge, Descartes opposed the empiricism of Francis Bacon. Bacon held that observation preceded theory, but Descartes thought that some observations could be illusory, so some theory, in the form of reason, had to come first. The point, for Descartes, was that the theory in question was the product of human reason, not of empirical experience. (Cartesian rationalism was such a counterpoint to Bacon's empiricism that Noam Chomsky has characterized his view of language, with its emphasis on innate grammatical knowledge, as "Cartesian linguistics" -- yielding the title of one of Chomsky's books.)
Anyway, when Descartes actually tried to apply his method, he quickly discovered that there was one thing that couldn't be doubted -- which was that he was engaged in the act of doubting. Such thoughts might well come from God, or else from a wicked demon, but they were still his thoughts. From this conscious experience of thinking, he inferred (in his Discourse on Method, 1637) that he must therefore exist:
He further concluded (in his Meditations, 1641) that mind was the essence of human nature:
With these inferences, Descartes changed the focus of philosophy from questions of metaphysics (i.e., the ultimate nature of reality) and ethics (i.e., the nature of proper human conduct) to questions of epistemology (i.e., the nature of knowledge). By reasoning that consciousness (mind) was composed of a different kind of substance than physical entities (body), Descartes further set the agenda for philosophical and scientific investigations of consciousness -- and specifically, of the relation between mind and body -- for the next 300 years and more, right up to the present day.
Of course, the mind-body problem goes back farther than Descartes. But interestingly, there appears to have been a time when there wasn't a mind-body problem at all -- because, to begin with, there wasn't a mind problem. That is to say, nobody, not even philosophers, were asking questions about the nature of the mind, not to mention the relation between mind and body.
An interest in consciousness is apparent as
early as the "Golden Age" of Greek philosophy, as
exemplified by Socrates, Plato, and Aristotle.
Questions about the nature of mind continued to be raised among ancient and medieval philosophers of the West, mostly in commentaries on Socrates, Plato, and (especially) Aristotle. So too among philosophers in East. But at least in Europe, until Descartes philosophers mostly debated questions of metaphysics (the nature of reality) and ethics (the nature of good conduct). The philosophical analysis of consciousness as such, and particularly the mind-body problem, really starts with Descartes, at the beginning of the Age of Enlightenment.
Philosophy in the Medieval period, roughly the 5th century to the 15th, consisted mainly of commentaries on existing texts. It was generally believed that everything worth knowing was already known, either by virtue of divine revelation (as in the Hebrew Bible and the New Testament) or by virtue of the work of ancient Greek philosophers like Socrates, Plato, and Aristotle. The Renaissance of the 15th and 16th centuries represented not simply a "rebirth" of learning (including the translation of Arabic texts into Latin), and the revival of the Greek spirit of critical inquiry, but also the rise of experimental philosophy, the birth of the scientific method, and a quantum leap in scientific knowledge. Leading figures in this scientific revolution instigated by Francis Bacon, during the 16th and 17th centuries, were Galileo, Kepler, and Newton. While the nature of the universe was interesting in its own right; Francis Bacon argued that "knowledge is power", leading to the development of a bourgeois science tied to capitalist interests in trade and manufacturing. In any event, new scientific discoveries about the universe, the world, and the body further undermined the authority of ancient texts.
With the coming of the Age
of Reason, the emphasis on rational, progressive,
liberal scientific thought spread further. Osborne
(1992) has summarized the key ideas of the 18th century
Enlightenment as follows:
Consciousness is a philosophical problem as well as a scientific problem, and in fact scientists who work on consciousness address empirically the same questions that philosophers ask through the exercise of reason -- and, as Howard Gardner noted in The Mind's New Science, his wonderful history of the origins of interdisciplinary cognitive science, philosophers get to check the scientists' answers!
So even though this
course gives philosophical inquiry into
consciousness somewhat short shrift, so that it can
focus on scientific inquiry, a little background in
philosophy wouldn't hurt anyone. To that end,
I have found the following resources particularly
And, of course, there is the book by
UCB's own John Searle, essentially a distillation
of his lecture course on the philosophy of mind:
In addition, I highly recommend Robert Wozniak's Mind and Body: Rene Descartes to William James (1992). This absolutely wonderful publication, which is the catalog for an exhibit of historical texts in psychology mounted at the National Library of Medicine in celebration of the 100th anniversary of American psychology, is available on-line at http://serendip.brynmawr.edu/Mind.
When psychology split off from
philosophy and physiology it, too, began with a focus on
consciousness. William James, in his Principles of
Psychology (1890), asserted that
by which he meant conscious mental life, and further noted that
Like Descartes, James identified "thinking" with any form of inner conscious mental activity. Thus he included percepts and memories as well as thoughts, and feelings and desires too.
In case his intentions weren't entirely clear, in his Psychology: Briefer Course (1892), James followed Ladd's definition of psychology:
Even before James, and before
psychology split off from sensory physiology, consciousness
played an important role in psychological theory and
and other proponents of the structuralist school
defined psychology as "the science of experience as
dependent on the experiencing individual", as opposed to
physics, which they defined as the science of experience as
independent of the experiencing individual. The
difference between psychology and physics is the difference
between determining how hot water must be to be painful and
how hot water must be to boil. By means of
experimental introspection, the structuralists attempted a
kind of mental chemistry, identifying the elementary
sensations and feelings out of which more complex
(conscious) mental states were built.
structuralists built a psychology of consciousness out of
introspection, the technique always made them nervous.
Science is supposed to be objective and public, but
introspection is necessarily subjective and private.
But so long as psychology was about the mental, it
appeared to be stuck with introspection. Accordingly,
some psychologists argued that the way to make psychology
truly scientific was to abandon the mental -- to define
psychology not as the science of mental life, as James did,
but as the science of behavior. This is what J.B.
Watson proposed in 1913, ushering in the behaviorist
revolution in psychology, later consolidated by B.F.
Skinner. Watson, Skinner, and their cohorts soon
reduced psychology to tracing the functional relations
between physical stimuli and muscular responses (as opposed
to psychophysics, which sought to trace the relations
between stimuli and sensory experiences). And
because behavior was behavior, the subject of choice shifted
from the human being to the white rat. Quickly,
psychology abandoned interest in all aspects of conscious
mental life -- perception, memory, thinking, emotion, and
motivation. As Robert S. Thorndike put it in his 1921
textbook, Psychology: A Study of Mental Life (p. 2,
First psychology lost its soul,
Then it lost its mind,
Then it lost consciousness;
it has behavior still, of a kind.
attributed the quip to "a wag", but the wag was almost certainly
himself. That somewhat wistful phrase, "of a kind",
suggests that Woodworth was responding to Watson's
"muscle-twitch" version of stimulus-response behaviorism (the
phrase is Watson's own, from his 1919 book), as opposed to the
emphasis of methodological behaviorists, such as Edward C.
Tolman, on "what the organism is doing" (I think this phrase
comes from Tolman).
Despite the hegemony of
behaviorism in psychology, interest in consciousness did not
entirely disappear within academic psychology.
began to return to psychology with the cognitive revolution
against behaviorism, but even then it re-entered the field
by the back door. That is, many landmark studies of
the cognitive revolution were essentially about
consciousness, even though they hardly ever used the word:
Owen Flanagan (1992) has discussed four reasons for the
avoidance of consciousness -- what he calls conscious
shyness -- among some quarters within cognitive
The difference between conscious inessentialism and the epiphenomenalist suspicion is that conscious inessentialism doesn't deny that consciousness has functional significance. It only denies that consciousness is required for certain mental and behavioral activities. The epiphenomenalist suspicion is the suspicion that consciousness doesn't have any functional significance after all.
Conscious shyness is bad news for psychology, because consciousness is our central problem. But paradoxically it is good news for those who want to promote the study of the psychological unconscious -- the idea that conscious experience, thought, and action is influenced by mental states and processes that lie outside phenomenal awareness. The ultimate outcome of the avoidance of consciousness has been the domestication of the unconscious: it's not just for Freudians after all (and, because Freudian theory is wrong in every detail, it's not for Freudians at all!).
Scientifically, the big question about consciousness is this:
In attempting to address this question, we come up with a number of other questions about consciousness.
This question is usually phrased in terms of
how the body affects the mind -- to wit, How does a physical
system like the brain, operating according objective and
impersonal electrical and chemical principles, give rise to
subjective and personal conscious experiences of perceiving,
remembering, thinking, feeling, and willing? This
question is essentially metaphysical, because it has to do
with the nature of reality: Are we required to posit two
different forms of existence, physical and mental, to
account for body and mind? And it gives rise to lots of
wonderful philosophical controversies, like dualism vs.
monism, and eliminative materialism. Still, these
metaphysical questions have some interesting implications:
The other half of the mind-body question is equally interesting: whether, and how, the mind can control the body. Partly this is a question of free will, traditionally addressed by philosophers and now addressed by psychologists as well (some of whom steadfastly deny that there's any such thing). But it's also a question of psychosomatics: can changes in mental state cause changes in bodily state, creating the potential for mind-body healing?
Although the mind-body problem is often presented in metaphysical terms, because it deals with whether mind and body are two different types of reality, the remaining problems of consciousness are largely epistemological in nature.
What does consciousness entail? Many philosophical debates about consciousness deal with such highly abstract issues as qualia and intentionality. Psychology confronted many of the same abstract problems in Titchener's introspective analyses of the structure of consciousness, and James's psychologizing about the stream of consciousness.
Descartes thought that his mind was the one thing he could know for sure, and this assumption set the stage for the structuralists' development of experimental introspection as the fundamental method for the new scientific psychology. But how good is introspection as a vehicle for knowing our minds? How valid are our percepts and memories? Do our thoughts and feelings have any privileged status, or are they nothing more than illusions and after-the-fact rationalizations? Can we actually observe the mental processes by which we create conscious percepts, memories, thoughts, feelings, and desires?
In a sense, the entire field of cognitive psychology (and the scientific study of emotion and motivation as well, for that matter), is an attempt to go beyond experimental introspection to determine the architecture of the mind, how mental processes operate within this structure, and how percepts, memories, thoughts, and the like are represented in our minds. Interestingly, for all the weeping and gnashing of teeth about the problems of introspection, cognitive psychology depends intimately, and inevitably, on self-reports. An investigator may be collecting data from button presses on a computer keyboard instead of a clinical interview or paper-and-pencil questionnaire, but the fact remains that if you're doing an experiment on perception, you're asking the subjects to tell you what they perceive, where, and when. Same goes for memory, thoughts, images, feelings, and desires. There's simply no getting around self-reports. The question for psychology, as Fechner and Wundt clearly understood, is how to make a science of them.
This course will not provide a complete introduction to cognitive psychology -- to some extent, we assume that you've already had that, at least at the level of an introductory course in psychology or cognitive science. But, because of the piecemeal approach that is characteristic of psychology, that course probably didn't have too much to say about consciousness. In this course, our interest in consciousness provides an overarching context for studying perception, memory, and other psychological phenomena.
It is now clear that our introspective knowledge of our own minds is incomplete. In the first place, the mental processes giving rise to conscious cognitive, emotional, and motivational states may lie outside our conscious control. Such processes are often labeled automatic, as opposed to controlled. Research on attention and automaticity suggests that at least some mental processes operate outside of conscious awareness, and voluntary control. In fact, there is some tendency to identify the psychological unconscious with these automatic processes.
However, the failure of introspection may also extend to mental states themselves. In psychology, there has been a general assumption that while conscious states -- what we perceive, remember, know, believe, think, feel, and want -- may be generated by automatic processes, mental states (or contents) themselves can't be unconscious. But there is now a large literature that suggests that mental states as well as mental processes can be unconscious -- that is, that our experience, thought, and action can be influenced by percepts, memories, and the like of which we are not aware. This viewpoint is best developed in the literature on implicit memory, but we will see how the implicit-explicit distinction can be extended beyond memory to other cognitive domains, such as perception and thinking, and beyond cognition to the domains of emotion and motivation. This body of research now indicates that it is indeed meaningful to speak of percepts, memories, and the like that are unconscious in the sense that they are inaccessible to introspective phenomenal awareness.
In a sense, the question of unconscious mental life returns us to the metaphysical question, of whether there are two kinds of mind -- one conscious and the other unconscious. If there is an unconscious mind, what is the difference that makes for consciousness? The difference between automatic and controlled processes, and between conscious and unconscious mental states provides another perspective on the neural correlates of consciousness.
In the case of implicit memory, people may not be conscious of certain memories, but they are still conscious. But we're not always conscious. In sleep, we seem to be unconscious, at least for a while. But dreams appear to represent a peculiar form of consciousness occurring during sleep. Other phenomena of sleep, such as sleepwalking and sleeptalking, also raise questions about consciousness, as does the possibility of sleep learning. While sleep occurs naturally, unconsciousness is induced artificially in surgical anesthesia. In coma, we really seem to be in a permanent state of unconsciousness -- but are we?
Even when we are consciousness, we sometimes experience states where our normal consciousness is radically altered. In the clinical dissociative and conversion disorders historically known as hysteria, people can't remember things that happened to them, can't see things that are right in front of them, and can't voluntarily execute certain movements. To some extent, hypnosis provides a laboratory model for these clinical symptoms.
Hysteria is very rare, and only a small minority of people are highly hypnotizable, but almost everyone experiences states of absorption and daydreaming, at least on occasion, and individuals who perform at very high levels often experience an exhilarating state of flow.
religious traditions, both Eastern and Western, have
meditative disciplines in which consciousness can be altered
(and the Eastern meditative tradition has been "Westernized",
and "secularized", to some extent by such technologies as
biofeedback. Meditation raises a number of interesting
questions about consciousness:
If percepts and memories are unconscious, how do we know they exist? And how would we know whether an individual is in an "altered" state of consciousness? These questions raise the basic question of how we know whether another person is conscious at all -- and, if they are conscious, what they're conscious of. Although we appear to have direct introspective access to the contents of our own minds, at least under some circumstances, our knowledge of other minds is necessarily indirect. We know another person's mental states only by inference. As suggested earlier, the question of the knowledge of other minds is addressed directly by cognitive psychology -- whose task it is to figure out what percepts, memories, and thoughts people have, and how these mental states are structured and processed. The knowledge of other minds is also the province of social psychology, which (especially in the study of social cognition) seeks to understand how we "perceive" other people and make sense of their behaviors.
Additionally, developmental psychologists are
interested in how children acquire a theory of mind --
the understanding not just that they themselves have mental
states. In the ontogenetic sense, this may be reflect the individual's development of
consciousness -- an appreciation of mental states as such,
and the emergence of the person as a sentient being who not
only has phenomenal experiences, but knows that he
or she has them.
knowledge of other minds also goes beyond our understanding
of other people, and extends both to nonhuman animals and
machines. Granted, at least for purposes of argument, that
adult human beings are conscious, does consciousness extend
to other biological creatures, and if so how far. And
does -- or could -- consciousness extend to machines
made out of silicon chips (or, for that matter, tin cans
linked by string), as well as living organisms made up of
Some philosophers, psychologists, and other cognitive scientists will tell you that the "hard problem" of consciousness is knowing how brains cause consciousness to occur. That's an interesting problem, but it's not the hardest problem of consciousness. The hardest problem of consciousness is knowing what's on another creature's mind.
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