Imagination, by Robert Grosseteste Imagination, by Robert Grosseteste

Imagination, Eliminativism, and the Pre-History of Consciousness.

by Nigel J. T. Thomas
To email me, click here

California State University, Los Angeles.

To contact the author, click here

Paper delivered at the Toward a Science of Consciousness (Tucson III) Conference, April 30th 1998.
[Abstract published in Consciousness Research Abstracts (3) 1998 p. 36.]

A somewhat revised version of this article has now been published in Danish translation as:
Thomas, N.J.T. (2006), "Fantasi, Eliminativisme og Bevidsthedens Forhistorie," Slagmark: Tidsskrift for Idéhistorie (46) 15-31.


The experts seem generally to agree that there was no word for consciousness in anything like its modern sense much before the 17th century. The Oxford English Dictionary does not list any earlier uses of the word, and it does not appear to have had any equivalents in other European languages either, including Latin and Ancient Greek(1). What is more, the philosophers of former times seem not to have been troubled by the mind-body problem (recently rechristened "the hard problem") despite the fact that it is effectively unavoidable for almost any modern who thinks seriously about the subject of consciousness. (If you don't think the "hard problem" is hard, you haven't thought hard about consciousness!)

Of course, the history of words, or even of concepts, does not in general tell you very much about things. The ancients did not have words for protons or wombats, but there were protons and wombats back then. However, consciousness is, arguably, a very special case in this regard. There were no concepts of proton or wombat because before the invention of particle accelerators and the discovery of Australia it was impossible for Europeans to observe them. But consciousness, as we now conceive it, is supposed to be the most near-at-hand and directly observable of all phenomena. It is always right there to be noticed, at almost every waking moment. How could its existence have gone unremarked through thousands of years of history (not to mention the eons of pre-history before that)?

There is a good answer to this, of course, and it is an important answer because it not only clears up this little philological puzzle; it also solves the mind-body problem itself. The answer is that consciousness does not exist. Rather than being like protons and wombats, it is like Zeus or phlogiston. People had long since gotten over believing in Zeus by the 17th century, but at around that time (probably because of that awful Descartes) they fell into an equally deluded belief in consciousness. Not long after, they fell into believing in phlogiston, too, but although they fairly soon got over that one, the struggle to get rid of the consciousness delusion continues.

This is by now, of course, a standard and familiar position in the philosophy of mind, known as "eliminativism" or "eliminative materialism". It is promoted, in various forms, by philosophers like Ryle (1949), Feyerabend (1963), Rorty (1980), Wilkes (1988, 1995), Dennett (1982, 1988, 1991), and the Churchlands (e.g. P. M. Churchland, 1979, 1981; P. S. Churchland, 1983, 1988), and by psychologists such as Watson (1930) and Skinner (1976)(2), and it is a position that has a great deal to recommend it. There can be little doubt that, if it is right, it really does solve the mind-body problem, cleanly. It is very radical, and it requires a good deal of intellectual sophistication to even begin to take it seriously; but surely a really hard problem calls for a radical and sophisticated solution.

I must confess to being quite tempted by eliminativism myself, especially when it comes to notions like "qualia", which have no currency outside technical, highly theoretical discussions. However, in the end I cannot attain the degree of intellectual sophistication required to disbelieve in consciousness. Consciousness is not a technical notion, but an everyday one, widely understood by the educated and uneducated alike, and it is present to me almost every waking moment. Surely it is more like thunderstorms and fire than like Zeus or phlogiston: rather than being a theoretical component of an explanation(3), an explanans ,it is an explanandum, a phenomenon that demands to be explained.

But if eliminativism about consciousness is false, the historical facts outlined above need some other explanation. I will try to give one, or at least a partial one. First of all we should note that, like thunderstorms and fire, indeed, like almost any natural phenomenon that is of any very general interest, consciousness is something very complex. The phenomenon of fire can be analyzed into various aspects--the heat, the flames, the smoke, the transformation of the fuel into ash, etc.--and each of these will call on different scientific resources for its explanation: thermodynamics, turbulent fluid dynamics, plasma physics, colloid theory, chemistry, etc. There is no single, unitary scientific account of fire (or thunderstorms, or life, or whatever), which is not to say that science cannot account for these phenomena perfectly well. Likewise, consciousness presents us not with one problem but with many.

Also, it is not inevitable that the various recognized subcomponents of a complex phenomenon must always go together in the same way. After all, there sometimes is smoke without fire, and fire without smoke. It may indeed be the case that the ancients and medievals did not have our concept of consciousness in the sense that they did not group together quite the same set of sub-phenomena under a single term. However, I want to suggest that their way of conceptually organizing the sub-phenomena of consciousness was not so wildly different from ours as to be truly alien, but just different enough to suggest possible new (or long neglected) ways of thinking about our current problems. Fire, it turns out, is best understood when we recognize that in some important ways it has more in common with slow, cool, non-luminescent processes, like rusting or cellular respiration, than it does with certain other hot, bright, violent phenomena like lightening. Things might be similar with consciousness.


If we want to understand how people thought about the mind before the time of Descartes, then we must look first to the works of Aristotle. It is not just that Aristotelianism dominated the middle ages; Aristotle was the first person that we know about who really wrote systematically about the mind, and his views about it had a formative influence in ancient times too. In particular, the so called Neo-Platonists took their psychology, if not their metaphysics, very largely from Aristotle rather than Plato (Wallis, 1972; Harris, 1976), and, largely through the mediation of St. Augustine, these ideas found their way into the Christian mainstream long before the rise of medieval Aristotelianism. To a very large extent, then, the question of whether there was a conception of consciousness before the 17th century becomes the question of whether there was an Aristotelian conception of consciousness.

It has often been claimed that Aristotle did not have a conception of consciousness(4). However, these claims seem largely to rest on the observation that he (and his followers) were not troubled by anything resembling the modern mind-body problem (Hardie, 1976). It is hard for a modern philosopher to imagine how you could believe in anything like consciousness and not be troubled by this problem: how could an alert philosopher, thinking of consciousness fail to sense both the allure and the problems of dualism? The tendency is to conclude that Aristotle could not have believed in consciousness, that for him and for his intellectual heirs up until the time of Descartes, something like eliminativism seemed like plain, uncontroversial common sense

But if it is true that the modern mind-body problem does not really pre-date Descartes, it does not follow that the problem arose because he conjured the concept of consciousness out of nowhere. To defend eliminativism now, even with all the considerable rescouses of eloquence, scholarship and passion that its contemporary advocates can and do muster, seems to be to fly quixotically in the face of the obvious. Could Descartes, brilliant as he was, have changed common sense so radically and deeply? No. The real basis of the intellectual revolution that Descartes helped to bring to fruition was a change in the conception of matter. In Descartes time, the forces of the scientific revolution were rapidly moving towards a new conception of matter as essentially dead and passive, subject only to the external pushes of efficient causation, and not the internal pulls of purpose and desire. His contribution was not just to help crystallize this view of matter (finally made compelling by Newton), but to be the pioneer in exploring its implications for our understanding of mind. Aristotle felt no mind-body problem because, for him, what we would now think of as mental qualities were inherent in all matter. Aristotle saw teleology, purposefullness, everywhere: in all material objects, not just in the heads of intelligent creatures. He would be better (if still anachronistically) characterized as a panpsychist rather than as an eliminativist.

The claim that Aristotle and Aristotelianism had no concept of consciousness, then, comes down to little more than the observation that he had no term that smoothly translates our "consciousness". He might not, indeed, have grouped the sub-phenomena of consciousness together under such a term in quite the way that we usually do now, but it does not follow that he did not recognize either their existence of their inter-relatedness. In fact, the Aristotelian scholar Deborah Modrak (1981) has argued that not only does Aristotle try to give an account of several key aspects of what we now call "consciousness", he does so in a unified way, explaining them all in terms of one and the same mental faculty.

Modrak particularly directs out attention to four mental phenomena which are, today, regularly ascribed to consciousness. These are (1) unity (the way our conscious states are experienced as being states of a single subject), (2) intentionality (the way our thoughts are experienced as being about something), (3) reflexive awareness (our capacity to be aware of our mental states, such as of the fact that we are perceiving something), and (4) our ability to recognize the relations between cognitive states of different types (such as recognizing the compatibility or incompatibility between a certain belief and a certain perception). According to Modrak (and her argument seems to be well grounded in the Aristotelian texts) Aristotle explained all these things, in a principled way, in terms of a single mental faculty, the so called "common sense". What is more, this faculty turns out also to be responsible for our awareness of passing time, for imagination (i.e. the experiencing of mental imagery), and for memory (understood as explicit recall). Wakefulness and sleep (consciousness and unconsciousness in the most straightforward sense) are also explained in terms of the activity or inactivity of this faculty. To all intents and purposes, according to Modrak, the "common sense" is the Aristotelian concept of consciousness.

Now at this point I ought to make it clear that the Greek terms that modern Aristotle scholars translate as "common sense" do not refer at all to what is meant by "common sense" in modern colloquial English. For that reason, it may be better to refer to it in the original Greek, as "koine aisthesis", or by the Latin expression that was used for it by the medieval Aristotelians: "sensus communis". Certainly it has nothing in particular to do with being a reasonable, sensible, level-headed sort of person. Rather, it gets its name from the fact that it is a perceptual function or activity that is common to all the various sense organs. It is the way in which the deliverances of sight, hearing, smell, taste and touch are brought together and integrated into meaningful perceptual wholes. Such a faculty is necessary, according to Aristotle, to explain how we can be aware that the whiteness that we see and the sweet fragrance that we smell belong to one and the same flower: that is, it is his solution to what is these days called "the binding problem". Like Crick and Koch (1990) and others in recent times, Aristotle implicitly sees such binding as lying at the heart of the problem of consciousness. His notion of sensus communis did not exactly provide a solution to this problem--after all, Aristotle has precious little to say about how it might actually work--but it did provide the basis for the conceptual map of the territory that has been guiding us ever since.

I think this is true, despite the fact that the notion of a common sense faculty, in the Aristotelian sense, has long since dropped out of our conceptual repertoire. It has been replaced, on the one hand, by the concept of consciousness, which we still think of as capable of handling and integrating information from all the various sense modalities, and on the other hand by the apparently quite distinct concept of imagination.

Although it would certainly be misleading to translate "koine aisthesis" and "sensus communis" simply as "consciousness", it is accepted practice to translate Aristotle's word "phantasia" as "imagination. Our word "imagination", after all, is a direct derivative of "imaginatio", which was the Latin equivalent of "phantasia" (and certainly it comes closer to Aristotle's meaning than etymologically more closely related modern words like "fantasy" or "fancy"). In fact, any implications of the fanciful or the unreal, or even the creative, have little or no overt place Aristotle's discussion of this topic. For him, imagination (phantasia) is "the process by which we say that an image [i.e. a mental image] is presented to us" (De Anima 428a)(5), and mental images (phantasmata) are, for him, essential to the rational processes of thinking (De Anima 431a, 427b; De Memoria 449b). To put it in anachronistically modern terms, images are the mental representations with which cognition works.

But mental images, as we conceive them now, are quintessentially conscious phenomena(6), and thus it should come as no surprise that the Aristotelian imagination is very closely related to the Aristotelian sensus communis. In fact, they seem to be presented as essentially a single faculty, regarded from different points of view, or functioning in different circumstances(7). Regarded in terms of its inputs, it is the sensus communis, integrating our sensory experience of bare colors, smells, sounds, tastes, and feels, and thus enabling the perception of meaningful objects and their spatio-temporal relations. In terms of its outputs it is the imagination, the faculty that makes the images that are the substrate of thought.

The middle ages, however, did not quite see things this way. Perhaps because the intellectual self-confidence of the medievals had been shattered by the centuries of barbarism following the collapse of Rome, the pressing intellectual task seemed to be to extract and Christianize as much as possible of the wisdom of the ancients from the corrupt texts of (especially) Aristotle that were again becoming available. The writings of Aristotle came to be seen as second in importance only to the Bible, and the exegetical skills honed on the Divine word were brought to bear on the words of The Philosopher. This focus on textual exegesis (and exegesis of exegesis) lead to a tendency to draw and stress fine distinctions, emphasizing conceptual discontinuities even where the continuities might seem more important. Thus, in medieval cognitive theory, imaginatio and sensus communis come to be treated as distinct faculties; indeed, we often find a distinction being drawn between imaginatio and phantasia, simply, it would seem, because the two different words were available(8).

This psychological taxonomy was combined with a sort of speculative neuroscience (based on ancient authors like Galen, Herophilus, and Nemesius rather than on Aristotle(9)) to produce a sort of rudimentary cognitive psychology with a general form that is not too unlike the box diagrams found in modern textbooks.

Figure 1.

The Medieval and Renaissance Brain.
Version of a diagram by Gregor Reisch, first published in 1503.
The underlying theory goes back much further (as do cruder versions of the diagram)
(see Clarke & Dewhurst, 1972).
[Click here, or on the picture, for a larger version.]

Diagrams more or less like figure 1 are found in many medieval and renaissance texts (Clarke & Dewhurst, 1972). It was believed that the real mental action went on in the cerebro-spinal fluid (animal-spirit) rather than in the solid parts of the brain, and so the cognitive functions were located in the major fluid filled ventricles of the brain. For most purposes there are assumed to be three of these, although some authors may have been aware that the most anterior ventricle is actually double, two ventricles in parallel (what modern anatomists call the lateral ventricles). In any case, we can easily abstract away from the lousy neuroscience. We are then left with a cognitive theory that is not so very different from the sort of thing that you might find in contemporary textbooks of Cognitive Psychology (figure 2). Sensory data comes into the front ventricle(s), which processes them into representations, images, and these are then manipulated and compared (thought about) in the middle ventricle. (It is labeled cogitativa and estimativa, the thinking and reckoning faculties.) The rearmost ventricle is memory, where images can be stored until needed again for thinking about. Contemporary cognitive theory (figure 2) labels its boxes differently, but their functions do not seem so very different, especially when we realize that the "Short Term Memory" box is standardly seen (explicitly or implicitly) as the arena where mental representations, (passed from the other two boxes) become conscious, and where conscious thinking (viewed as manipulation of such representations) takes place (Carr, 1979).

Figure 2.
The bare bones version of contemporary Cognitive theory.

But I want to direct your attention now to the 'front ventricle'. Note that it contains three faculties, sensus communis, fantasia, and imaginativa. On the one hand it is interesting that they are distinguished. Note, particularly, the small bulge shown at the front of the ventricle. Although it is not obvious in this version of the diagram, in other versions it is clear that this is there in order that sensus communis can be given a place that is a little more anterior than its fellows (certainly it has nothing to do with the realities of anatomy). Sensus communis is the input stage, fantasia and imaginativa output the finished representations into the middle ventricle.

Note also, however, that these faculties do all share the same ventricle. This is a trace of the fact that, as originally conceived they were not meant to be truly distinct from one another. Finally, however, note that all the faculties in all three ventricles are essentially dealing with mental images (phantasmata), with conscious thought contents. The mind is conscious throughout, and no-one is worrying about the mind-body problem.

Descartes, of course, changed this picture enormously, and set the agenda for subsequent discussion of the mind. But to understand what he really did we must not look only at his purely philosophical work--the Meditations, the Discourse on Method, the stuff that is pored over in philosophy seminars today the way the medievals pored over Aristotle. The roots of Descartes' philosophy, and his main influence on his immediate posterity, are to be found in his more scientific works; the relevant one here being the Treatise on Man, where we find figures like the following:

Figure 3.
Diagram from Descartes' Treatise of Man (1664).


Figure 4.
Diagram from Descartes' Treatise of Man (1664).

Although Descartes presented himself as breaking explicitly and sharply with Aristotle and with the medievals, in fact, inevitably, he still shared many of their assumptions. Thus, the cerebro-spinal fluid (CSF), the animal spirit, still does the work in the Cartesian brain, although Descartes thought of it as subserving an elaborate hydraulic system of tubes (nerves) and valves, rather than as being the medium in which ideas float.

More importantly, he still retains the basic threefold division of faculties as seen in figure 1 and figure 2. However, they are arranged radically differently. Memory is distributed around the brain: in a fairly modern way, it is seen as encoded in subtle changes in the arrangement and connectivity of the nerves that compose the neural matter. The cognitive and reckoning functions of the middle ventricle are treated quite differently, however. In his most notorious conceptual innovation, Descartes took these out of the brain, and out of the physical universe altogether, and assigned them to an immaterial soul.

It is well known that Descartes thought of this soul primarily as the locus of rationality, and he thought that it was able, by itself, to construct the famous proofs of its own existence and of the existence of God that we find in the Meditations. Indeed, he thought that it could also construct mathematics and much of physics all without having to rely on input from the unreliable senses. The fact that Descartes thought reason could know so much through its own internal resources may help to explain why the mind-body problem, the problem of how such an immaterial soul could hook-up to the physical universe, never looked nearly so insurmountable to Descartes himself as it has done to his successors. The Cartesian soul was not, primarily, for being aware of qualia, it was for thinking: for philosophy, mathematics and a priori physics, and its essential mode of awareness would seem to be propositional. If Descartes presses the soul into service to explain our awareness of qualities, and thus originates the modern notion of qualitative consciousness, this appears almost as an afterthought in his system. With the rest of the person reduced to dead, soulless matter, the soul may be the only place that subjective experience has left to go. But clearly, its most basic function in the Cartesian scheme is to account for rational thought, not sensuous experience.

In the old scheme, the place for sensory experience was, surely, in the front ventricle with the common sense and the imagination, and it is not always remembered that Descartes did have a place for these faculties in his system. As we can see in figure 3, Descartes thought that the optical images formed at the back of the eyes gave rise to a further image, traced by the flow of animal spirits through the nerves, on the surface of the pineal gland. Likewise, olfactory information from the nose, and information from the other senses as well, is all brought together at the pineal surface. Descartes explicitly identifies the pineal surface as both the sensus communis and the imagination, and he refers to the images formed there as "ideas" ["idées" in the French] (Descartes, 1644).

Now remember that for Aristotle it was the sensus communis/imagination that subserved most of the functions of modern consciousness. But Descartes has shrunk this function down to the two-dimensional surface of a tiny gland, and directed everyone's attention decisively away from this unregarded function to the mysteries of the immaterial rational soul. However, of course, the pineal surface does play a prominent and crucial role in Descartes' overall system; it (and I do mean the surface, not the gland as a whole) is the locus of communication between the body and the immaterial soul. It may not be consciousness itself, but it is the marvelous threshold of consciousness, the place where the physical and mental realms inexplicably come together.

Of course, the pineal was soon discredited in this role; on the one hand by advances in neuroanatomy, and on the other hand by the realization that shrinking the locus of interaction down to a small area really does nothing to alleviate the basic problem of understanding the interaction of material and immaterial substances. Descartes vision of the imagination as constituting the interface between mind and body was forgotten in favor of a vision in which the interface is set aside as quite ineffable, and imagination becomes just one more of the mysterious functions of the mind/soul, a function that remains mysterious no matter how vehemently it is insisted that the mind is really material. Instead of the notion that (material) images are presented to the soul at the pineal surface, we move to a picture of a soul with sensory images (ideas, impressions, whatever) somehow floating in the ectoplasm (or, rather, in the we-know-not-what), as they once floated in the CSF of the ventricles. We find this picture of the mind perhaps most clearly in Hume (1739), for whom the mind and the imagination are scarcely distinct. However, imagination is not longer the mental image forming capacity, but more the psychic space in which these already mental objects float and clump together. Whatever we may think of associationism, this picture of the mind, full of mysterious, non-physical, qualitative objects, still deeply infects our contemporary understanding of consciousness.


You do not have to be a substance dualist, or at all preoccupied with qualia, to be worried about the body-mind interface. Even the strictest materialist should realize that there is a problem in understanding how intrinsically meaningless physical objects or energies can constitute meaningful thoughts. A scientific theory of imagination, I want to suggest, may be the missing piece of the puzzle of consciousness: the piece that can fit the body and the mind back together, just as it held them together, albeit tenuously, in the Cartesian system. We should be doing all we can to construct a scientific account of the function that Aristotle designated as the imagination and the common sense. Aristotle himself could not (at any rate, he did not) give any such account, but in recent decades we have learned things far beyond the dreams or either Aristotle or Descartes about the characteristics and mechanisms of both perception and mental imagery. However, as Baars (1996) has recently noted, most contemporary work on imagery pays little or no attention to its intimate relationship to consciousness(10). Bringing our scientific knowledge of imagery to bear on the problem of consciousness, and attempting to theorize imagery as a fundamentally conscious phenomenon, may transform our understanding of both topics; but this is work that still lies before us(11).


Notes

1. See Wilkes (1988, 1995), Rorty (1980). Zachary Mayne's Essay on Consciousness (1728) claims to be the first work devoted to the subject, although, of course, European philosophers had certainly been discussing the subject since Descartes. As for non-Europeans, Wilkes (1988, 1995) claims that there is no word even in modern Chinese (or Korean, and, by implication, other non-Western languages) that satisfactorily translates "consciousness".

2. More moderate eliminativists (Ryle, Wilkes, Dennett) seek only to eliminate consciousness (and other mentalistic concepts) from the ontology of natural science. Others expect and hope that this will be followed by its elimination from all human discourse. The historicist argument given above is developed most fully by Rorty and Wilkes. I do not mean to imply that it is the only extant argument for eliminativism, but it is amongst the strongest, and, with the possible exception of Dennett, all the eliminativists familiar to me lean, more or less heavily, on some form of historicist argument--although they may differ over whether the conceptual arcadia is best sought in the past (Rorty, Wilkes), the future (the Churchlands, Watson, Skinner), or amongst the philosophically innocent of the present (Ryle). Sometimes the history used is very questionable, as when Watson (1930) castigated all mentalistic concepts as "mediaeval". The Rorty-Wilkes version seems to be better grounded in historical reality.

3. See Horton (1967) for a classic defense of the explanatory, theoretical and science-like, function of supernatural entities such as polytheistic gods.

4. For references to such claims see Hardie (1976) and Modrak (1981). Rorty (1980) and Wilkes (1998, 1995) concur, of course.

5. For a defense of the view that this notion still remains at the core of modern usage of "imagination" and its cognates, see Thomas (1997a).

6. I am referring here to "folk" conceptions. Some cognitive scientists might want to disagree (e.g. Paivio, 1977; Kosslyn, 1983), but, as I have argued elsewhere (Thomas, 1997b; in press), the "folk" position is more defensible.

7. This broad interpretation is defended by Beare (1906 p. 296) and Ando (1965 pp. 123-5). The most direct (though not the only relevant) textual support comes at De Somniis (459a).

8. These latter medieval distinctions seem to have been drawn differently by different authors, and although, of course, they draw on the same linguistic resources, they appear to bear little or no relation to the still famous distinction drawn by Coleridge (1817) between imagination and "fancy".

9. See Woolam (1957); Clarke & Dewhurst (1972); Bruyn (1982). It may have been the Alexandrian anatomist Herophilus (died c. 255 B.C.) who originated the idea that the mental faculties were seated in the brain's ventricles, but this was not accepted by his principal intellectual heirs, Erasistratus and Galen. Nemesius (c. 340-379 A.D.) seems to have been principally responsible for propagating the idea. St. Augustine, whose writings, of course, carried enormous authority for Christian scholars, probably picked up the idea from him (Bruyn, 1982). The wide acceptance of this theory in the middle ages may thus have derived largely from the fact that Nemesius was one of the very few Christians to have written in an informed way on neuroanatomy in classical times.

10. For reviews of contemporary work on imagery see Morris & Hampson (1983), Finke (1989), and Kosslyn (1994). As counterbalance to the last, important but very partial, account, see Pylyshyn (1994) and Thomas (in press).

11. For an attempt to begin it, see Thomas (in press).


References

Ando, T. (1965). Aristotle's Theory of Practical Cognition. Martinus Nijhoff. The Hague.

Baars, B. J. (1996). "When are Images Conscious? The Curious Disconnection between Imagery and Consciousness in the Scientific Literature," Consciousness and Cognition (5) 261-264.

Beare, J. I. (1906). Greek Theories of Elementary Cognition: From Alcmaeon to Aristotle. Oxford University Press. Oxford.

Bruyn, G. W. (1982). "The Seat of the Soul," in: F. C. Rose & W. F. Bynum (eds.) Historical Aspects of the Neurosciences (pp. 55-81). Raven Press. New York.

Carr, T. H. (1979). "Consciousness in Models of Human Information Processing: Primary Memory, Executive Control and Input Regulation," in: G. Underwood & R. Stevens (eds.) Aspects of Consciousness, Vol.1: Psychological Issues (pp. 123-153). Academic Press. London.

Churchland, P. M. (1979). Scientific Realism and the Plasticity of Mind. Cambridge University Press.

Churchland, P. M. (1981). "Eliminative Materialism and the Propositional Attitudes," Journal of Philosophy (78) 67-90.

Churchland, P. S. (1983). "Consciousness: The transmutation of a concept," Pacific Philosophical Quarterly (64) 80-95.

Churchland, P. S. (1988). Neurophilosophy: Toward a unified philosophy of the mind-brain. MIT Press. Cambridge MA.

Clarke, E. & Dewhurst, K. (1972). An Illustrated History of Brain Function. Sandford Publications. Oxford.

Coleridge, S. T. (1817). Biographia Literaria. (Edited by G. Watson. Dent. London. 1975)

Dennett, D. C. (1982). "How to Study Human Consciousness Empirically, or: Nothing Comes to Mind," Synthese (53) 159-180.

Dennett, D. C. (1988). "Quining Qualia," In: A. Marcel & E. Bisiach (eds.). Consciousness in Contemporary Science. New York: Oxford University Press. pp. 42-71.

Dennett, D. C. (1991). Consciousness Explained. Little, Brown. Boston MA.

Descartes, R. (1664). Treatise of Man. (Translated by T.S. Hall. Harvard University Press. Cambridge MA. 1972.)

Feyerabend, P. K. (1963). "Mental Events and the Brain," Journal of Philosophy (60) 295-296.

Finke, R. A. (1989). Principles of Mental Imagery. MIT Press. Cambridge, MA.

Hardie, W. F. R. (1976). "Concepts of Consciousness in Aristotle," Mind (85) 388-411.

Harris, R. B. (1976). "A Brief Description of Neoplatonism," In: R. B. Harris (ed.). The Significance of Neoplatonism. International Society for Neoplatonic Studies. Norfolk, VA. pp. 1-20.

Horton, R. (1967). "African Traditional Thought and Western Science," Africa (27) 50-71 & 155-187.

Hume, D. (1739). A Treatise of Human Nature. (Edited by L. A. Selby-Bigge & P. H. Nidditch. Oxford University Press. Oxford. 2nd edition, 1978).

Kosslyn, S. M. (1983). Ghosts in the Mind's Machine: Creating and Using Images in the Brain. Norton. New York.

Kosslyn, S. M. (1994). Image and Brain: The Resolution of the Imagery Debate. MIT Press. Cambridge, MA.

Mayne, Z. (1728). Two Dissertation Concerning Sense, and the Imagination. With an Essay on Consciousness. J. Tonson. London. (Facsimile reprint, Garland Publishing, New York. 1976.)

Modrak, D. K. W. (1981) "An Aristotelian Theory of Consciousness?" Ancient Philosophy (1) 160-170.

Morris, P. E. & Hampson P. J. (1983). Imagery and Consciousness. Academic Press. London.

Paivio, A. (1977). "Images, Propositions and Knowledge," in: J. M. Nicholas (ed.). Images, Perception and Knowledge. Reidel. Dordrecht/Boston MA.

Pylyshyn, Z. W. (1994). "Mental Images on the Brain," Nature (372) 289-290.

Rorty, R. (1980). Philosophy and the Mirror of Nature. Blackwell. Oxford.

Ryle, G. (1949). The Concept of Mind. Hutchinson. London.

Skinner, B. F. (1976). About Behaviorism. Vintage Books. New York

Thomas, N. J. T. (1997a). "Imagery and the Coherence of Imagination: A Critique of White," Journal of Philosophical Research (22) 95-127.

Thomas, N. J. T. (1997b). "Mental Imagery," in E. N. Zalta (ed.). The Stanford Encyclopedia of Philosophy. WWW online serial. URL: http://plato.stanford.edu/entries/mental-imagery/

Thomas, N. J. T. (in press). "Are Theories of Imagery Theories of Imagination? An Active Perception Approach to Conscious Mental Content," Cognitive Science.

Wallis, R. T. (1972). Neoplatonism. Duckworth. London.

Watson, J. B. (1930). Behaviorism (Revised 2nd edition). University of Chicago Press. Chicago.

Wilkes, K. V. (1988). "__, Yishi, Duh, Um, and Consciousness," in: A. J. Marcel & E. Bisiach (eds.). Consciousness in Contemporary Science (pp. 16-41). Oxford University Press.

Wilkes, K. V. (1995). "Losing Consciousness," in: T. Metzinger (ed.). Conscious Experience. Schöningh/Imprint Academic. Paderborn/Thorverton. pp. 97-106.

Woollam, D.H.M. (1957). "The Historical Significance of the Cerebrospinal Fluid," Medical History (1) 91-114.

To contact the author, click here
Mail me


Return to Home Page:
Imagination, Mental Imagery, Consciousness, Cognition:
Science, Philosophy & History.

Imagination, mental image, consciousness, cognition