Preprint version: appeared in Axiomathes 12: 55-85, 2001

THREE FACETS OF CONSCIOUSNESS 

David Woodruff Smith
University of California, Irvine

Abstract: Over the past century phenomenology has ably analyzed the basic structures of consciousness as we experience it. Yet recent philosophy of mind, looking to brain activity and computational function, has found it difficult to make room for the structures of subjectivity and intentionality that phenomenology has appraised. In order to understand consciousness as something that is both subjective and grounded in neural activity, we need to delve into phenomenology and ontology. I draw a fundamental distinction in ontology among the form, appearance, and substrate of any entity. Applying this three-facet ontology to consciousness, we distinguish: the intentionality of consciousness (its form), the way we experience consciousness (its appearance, including so-called qualia), and the physical, biological, and cultural basis of consciousness (its substrate). We can thus show how these very different aspects of consciousness fit together in a fundamental ontology. And we can thereby define the proper domains of phenomenology and other disciplines that contribute to our understanding of consciousness.

1.	The Problem of Consciousness

	Lately, philosophers and scientists have been looking for mind in all the wrong places. Physicalists of all stripes have been looking primarily at the physical conditions of consciousness, from neural activity to computational function. Meanwhile, humanists Ñ historicists, postmodernists, culture critics Ñ have looked primarily to the cultural conditions of our discourse, as if consciousness did not exist in its own right (expressed in art and literature) but is only ÒtheorizedÓ in a cultural tradition of phenomenology or science or humanistic discourse. Obviously, we have much to learn from the empirical sciences about boson, atom, organism, evolution, and brain Ñ and from humanistic observations in art, literature, and cultural history and criticism. But this learning is informed by further disciplines that are not ÒempiricalÓ or ÒnaturalisticÓ or indeed ÒhumanisticÓ in the received ways. If we are to understand the mind, we must understand more clearly the philosophical disciplines of phenomenology and ontology. It is these disciplines that define the place of mind in a world further detailed by the scientific disciplines of neuroscience, evolutionary biology, and quantum physics, as well as the humanistic disciplines of literary, artistic, and cultural criticism.
	Let us begin with a fundamental principle of ontology. The nature of any entity, I propose, divides into three aspects or facets which we may call its form, appearance, and substrate. In an act of consciousness, accordingly, we must distinguish three fundamentally different aspects: its form or intentional structure, its appearance or subjective ÒfeelÓ, and its substrate or origin. In terms of this three-facet distinction, we can define the place of consciousness in the world. The aim of this essay is to lay out this distinction in the nature of consciousness, and to draw out its implications for phenomenology and ontology, as distinct from purely naturalistic philosophy of mind. (I shall not focus here on humanistic theory, though I think the morals to follow have relevance for humanistic as well as naturalistic theory of mind.)
	Consciousness is the central concern of phenomenology. While there is more to mind than what we consciously experience, our theory of mind must begin with the salient part of mind, conscious intentional experience. Consciousness is characteristically a consciousness ÒofÓ something, as Husserl stressed circa 1900, and this property of directedness he dubbed intentionality. The literature of phenomenology Ñ in Husserl, Heidegger, Sartre, Merleau-Ponty, Ingarden, F¿llesdal, and others, with roots in Kant, Hume, Descartes, and still earlier thinkers Ñ has analyzed a rich variety of structures of intentionality in perception, imagination, thought, language, and action, along with properties of subjectivity, intersubjectivity, temporality, and the unity of the subject or self. For the discipline of phenomenology, there is no problem about the nature or existence of consciousness: we experience it first-hand throughout our waking life, and we have ways of studying it carefully.
	For recent philosophy of mind, however, consciousness has seemed problematic, either in its nature or in its very existence: because it seems to escape the story told by the physical sciences. ÒConsciousness is what makes the mind-body problem really intractable,Ó Thomas Nagel observed, rightly, wryly, and presciently in 1974 (Nagel 1974). As cognitive science developed over the next two decades, moving from artificial intelligence into neuroscience, consciousness regained center stage. The function of mind in mediating behavior, in problem-solving computation, in evolutionary adaptation, etc., did not seem to involve the subjective qualities of sensation, dubbed qualia, or the felt character of consciousness as directed toward objects in the world around one. Nonetheless, by 1990 neuroscientists were measuring properties of neural activity (such as spiking frequency) associated with consciousness, and so consciousness became a respectable phenomenon of scientific investigation. ÒConsciousness studiesÓ emerged with large interdisciplinary conferences in Tuscon in the 1990s. Still, amid the excitement even in popular media, David Chalmers (1996) echoed NagelÕs sentiment in declaring consciousness the ÒhardÓ problem for our theory of mind. Chalmers struck a nerve.
	Yet is it not odd to find consciousness problematic? What if someone declared that we do not know what language is, or that its existence is uncertain? We all speak a language such as English or Japanese. Grammarians have charted its basic forms such as the verb or noun phrase, and linguists have analyzed its ÒdeepÓ structure. How the brain functions in the production and understanding of language is a further matter of empirical neuroscience; how speech and writing emerged in our species is a matter of evolutionary biology; how our language shapes our society and politics is a matter of social-cultural theory. But the syntax and meaning of modern English are familiar, more or less, to its speakers. Similarly, the shape and meaning of our everyday experiences of perception, thought, and action are familiar to us all, more or less. These forms of consciousness have been studied by phenomenologists, much as linguists have studied forms of language. How the brain functions in consciousness, how our forms of experience evolved in the species Homo sapiens sapiens, how our consciousness is shaped by our language, culture, and politics Ñ these are further matters. But how can consciousness itself be thought problematic or its basic forms obscure?
	There is a widespread opinion that science alone will explain the workings of the world, including our own minds and thus consciousness. This idea goes under the positive banner of ÒnaturalismÓ or meets the pejorative charge of ÒscientismÓ. This attitude is expressed with characteristic verve, in his recent book Consilience (1998), by biologist Edward O. Wilson, famous for his studies of ants and for his conception of sociobiology. Quoting at length (the only way to evidence ÒattitudeÓ, albeit in the way of humanists):

Belief in the intrinsic unity of knowledge ... rides ultimately on the hypothesis that every mental process has a physical grounding and is consistent with the natural sciences. The mind is supremely important to the consilience program [of unity] for a reason both elementary and disturbingly profound: Everything that we know and can ever know about existence is created there.
	The loftier forms of such reflection and belief may seem at first to be the proper domain of philosophy, not science. But history shows that logic launched from introspection alone lacks thrust, can travel only so far, and usually heads in the wrong direction. Much of the history of modern philosophy, from Descartes and Kant forward, consists of failed models of the brain. The shortcoming is not the fault of the philosophers, who have doggedly pushed their methods to the limit, but a straightforward consequence of the biological evolution of the brain. All that has been learned empirically about evolution in general and mental process in particular suggests that the brain is a machine assembled not to understand itself, but to survive. Because these two ends are basically different, the mind unaided by factual knowledge from science sees the world only in little pieces. It throws a spotlight on those portions of the world it must know in order to live to the next day, and surrenders the rest to darkness. [Wilson 1998, 96.]

What we have here is failure to communicate, between philosophers and scientists. (1) It was philosophers Ñ Descartes, Kant, and Husserl Ñ who taught us the principle, ÒEverything that we know and can ever know about existence is created there [in the mind].Ó (2) The history of modern philosophy includes much more than failed models of the brain; Descartes and Husserl developed successful models of consciousness, of mind as experienced, precisely what is now found ÒhardÓ for empirical neuroscience. (3) While the brain did not evolve to understand itself, in humans it seems to be on the verge of producing, Wilson thinks, a scientific theory of its own physical and evolutionary function Ñ and, I think, a philosophical theory of consciousness. (4) Most of the great modern philosophers Ñ notably Descartes, Kant, and Husserl Ñ theorized in the face of factual knowledge from science cum mathematics in their day; they also appreciated, however, the importance of introspection when attending to the mind. (5) It is a hallmark of modern philosophy Ñ and ultimately philosophy of science Ñ to delimit knowledge of empirical fact and that of logic and mathematics, and thus to define the limits of both a posteriori and a priori knowledge; today in philosophy-and-science of mind we need to understand the boundaries and interrelations between the more empirical and the more ÒformalÓ aspects of consciousness.
	A different view, from the formal side of natural science, is proposed by mathematical physicist Roger Penrose in Shadows of the Mind (1994). From Kurt GšdelÕs incompleteness theorem in mathematical logic, Penrose argues that consciousness cannot be a process of computation in the technical sense originally defined by Alan Turing; then, from considerations of quantum mechanics and the microstructure of neurons in the human brain, Penrose argues that we need a non-computational quantum physics to explain how consciousness can arise in neuronal activity. I cannot evaluate the controversial speculations in PenroseÕs book, but if he is right then consciousness is defined by a very different kind of ÒformalÓ mathematical structure than anything philosophers of mind have been considering previously. What I like in PenroseÕs vision is this type of abstraction. The mathematical form of a piece of physical theory is integral to its content, and mathematical form is suggestive of ontological form. The subtitle of the Penrose book is A Search for the Missing Science of Consciousness. When we have finished the ÒscienceÓ of consciousness, its physics and its evolutionary biology, there will still be something missing in our account of consciousness. What is missing in all current ÒnaturalisticÓ thinking about consciousness is the relevant phenomenology and ontology, and their integration.
	The Òloftier formsÓ of naturalism are what attract the philosopher. I believe in the unity of knowledge. I believe moreover in the unity of the world: one world in which physical, mental, and cultural phenomena take their interweaving places. And I believe that every mental process has a physical grounding and is consistent with the natural sciences. (In fact, I am quite partial to the metaphor of ÒgroundÓ in ontology, as we shall see). So far, naturalism: both methodological and ontological (these need to be distinguished).
	However, the structure of intentionality Ñ call it ÒformalÓ or ÒtranscendentalÓ or something else Ñ does not flow easily from empirical, ÒnaturalisticÓ studies of the brain or bodily behavior or physical system alone. The ÒlogicÓ of intentionality in phenomenology, methodically launched from introspection alone, has a powerful thrust and carries us far (contrary to what Wilson claims in the quotation above). However, I must concur, the theory of intentionality carries us in different directions than empirical science: into structures of consciousness in phenomenology, and indeed into structures of thought and inference in logic and semantics (concerning how we reason and represent things in thought and language). ÒFormalÓ ontology too moves in different directions, positing fundamental categories of existence such as Individual, Property, Relation, Number, Part, etc. Both phenomenology and ontology are crucial to a unified system of knowledge Ñ of a unified world. And both carry us beyond naturalism: their results should be consistent with natural science, but the proper results of phenomenology and ontology are not simply amassed in empirical investigation in the natural sciences alone.
	When we want to see the world as a whole, and not in the Òlittle piecesÓ so effectively modelled by physics, chemistry, and biology, Ñ when we want to see the unity of the world, we must inform natural science with fundamental ontology. Much as physics needs mathematics to structure its empirical content, so natural science in general needs ontology Ñ or meta-physics Ñ to structure empirical content. And when we turn to the nature of mind itself, the empirical analysis of our own consciousness is pursued expressly and methodically by phenomenology. Moreover, it is ontology that must define the type of relation that holds between mind and its grounding in brain activity. This is a matter of formal ontology, rather than of empirical investigation per se.
	Wilfrid Sellars (1963) contrasted two ranges of theory that define respectively the ÒmanifestÓ image and the ÒscientificÓ image of man, that is, ourselves and our world as understood by common sense and as described by modern science. Similarly, in The Crisis of European Sciences and Transcendental Phenomenology (1938/1970) Husserl distinguished the Òlife-worldÓ from the Ònatural worldÓ, that is, the world as we experience it in everyday life and as we ÒmathematizeÓ it in physics. Mathematical physics (in all its well-earned glory) is an abstraction, Husserl held, from the world as experienced in everyday life. Consequently, Husserl said, we must confront Òthe paradox of human subjectivityÓ: how can I be both subject and object of consciousness, both a conscious subject and an object in nature? Husserl did not clearly foresee the ÒmathematizationÓ of thought in the computer model of mind. Yet todayÕs controversy about mind as computer (whatever the architecture, classical or connectionist) is but the application of mathematical modelling or ÒmathematizingÓ to mind as opposed to physical activity like planetary motion. Thus, HusserlÕs ÒparadoxÓ foreshadowed what today is the ÒhardÓ problem of consciousness: how can consciousness be both a subjective character of experience and an objective property of the brain Ñ a computational structure implemented in neural networks evolved over the natural history of the human species on the planet Earth in the cosmos that took shape since the Big Bang over 12 billion years ago amid fields of gravity, electromagnetism, and quantum superposition?
	Husserl distinguished phenomenology from both everyday knowledge and scientific knowledge, and he distinguished ÒformalÓ ontology from ÒmaterialÓ ontologies of Body, Culture, and Consciousness (as the distinction is reconstructed in D. W. Smith 1995). The point to stress here is that the world is characterized in different parts and levels in these different ranges of theory, and the philosophy of mind must respect these differences of theory.
	Only by understanding more clearly both phenomenology and ontology, along with the natural sciences (as well as the humanities), can we understand the place of consciousness in the world. That is the loftier moral of this essay. The specifics to follow concern the ontology of the three aspects or ÒfacetsÓ of consciousness, and the role of phenomenology in such an ontology.

2.	Phenomenology and Ontology

	Ontology (or metaphysics) is the science of being: as Aristotle put it, being as being. Where the special sciences Ñ physics, chemistry, biology, psychology, etc. Ñ are sciences of particular kinds of beings, ontology is the general science of what it is to be a being (and perhaps of what it is to be).
	Phenomenology is the science of consciousness: as Husserl put it, of consciousness as we experience it. Phenomenology begins in the description of conscious experience from our own point of view as subjects or agents: ÒI feel angryÓ, ÒI see that volcanoÓ, ÒI think that Plato was ironicÓ, ÒI will [to act so that I] stroke this tennis ball cross-courtÓ, and so on. The intentionality of consciousness is evident in our own experience: I am conscious ÒofÓ or ÒaboutÓ such-and-such.
	Now, ontology and phenomenology interact in our overall theory of consciousness and its place in the world. For our experience Ñ in emotion, perception, thought, and action Ñ is informed by our understanding of the world around us, by our ontology, implicit or explicit. And as we practice phenomenology, we use our ontology, implicitly or explicitly, in order to describe our experience, its intentional relation to objects in the world, and the things we are conscious of in perception, thought, and action. In this way, phenomenology is ontological. But ontology itself is phenomenological insofar as it recognizes the existence of our own consciousness Ñ as we must in saying what exists.
	It may be surprising to speak of ontology within the practice of phenomenology. For did not Husserl, in Ideas (Books I and I, 1913/1969 and 1912ff/1991), enjoin us to bracket the existence of the surrounding world of nature (and culture) in order to describe the structure of our consciousness? Here lies confusion. Husserl assumed a good deal of ÒformalÓ ontology Ñ concerning individual and essence, part and whole, dependence, etc. Ñ precisely as he sought to describe the essence of intentionality in phenomenology; and bracketing the region of nature (and the region of culture) leaves the region of consciousness, with the ÒmaterialÓ ontology of consciousness as part of phenomenology. (See D. W. Smith 1995.) Heidegger followed suit, in The Basic Problems of Phenomenology (1927/1975/1988), assuming his own formal categories in describing structures of our existence and comportment; indeed, Heidegger insisted that phenomenology is Òfundamental ontologyÓ, and so fundamental ontology is essentially phenomenological. Philosophy today has lost sight of the intimate connection between our saying what there is and our saying how we experience what is.
	Let us approach the nature of consciousness and its place in the world by laying out a very basic ontological distinction, a distinction we rarely make explicit but assume deep in the background of a good deal of our theorizing about the world.

3.	Three-Facet Ontology

	Everything in the world Ñ every entity whatsoever Ñ has a nature that divides fundamentally into three aspects we shall call facets: its form, its appearance, and its substrate. Thus:
(1)	The form of an entity is how or what it is: its whatness or quiddity Ñ the kinds, properties, relations, that make it what it is.
(2)	The appearance of an entity is how it is known or apprehended: how it looks if perceptible (its appearance in the everyday sense), but also how it is conceived if conceivable, how it is used if utilizable Ñ how it is experienced or ÒintendedÓ as thus-and-so.
(3)	The substrate of a thing is how it is founded or originated: how it comes to be, where it comes from, its history or genetic origin if temporal, its composition or material origin if material, its phylogenetic origin if biological, its cultural origin if a cultural artifact Ñ in short, its ecological origin in a wide sense, and ultimately its ontological origin in basic categories or modes of being.
The three facets of an entity (in this technical sense) are categorially distinct aspects of the entity, with important relations among them, as we shall be exploring. This distinction of aspects we may call the three-facet distinction. The distinction is depicted in a diagram in FIGURE 1.

					 	FORM
						     |
						entity
					         /	               \
			        SUBSTRATE                     APPEARANCE

FIGURE 1: The Three Facets of an Entity

	Distinctions among form, appearance, and foundation or origin have been drawn in philosophy since its inception. Plato distinguished concrete things from their forms, and appearance from reality, and posited forms as the foundation of being. Before Plato, Anaximander assessed the material composition of things and envisioned their origin or foundation in something more basic (an archaic quantum field?); he even foresaw biological evolution, 2500 years before Darwin. In more recent centuries, epistemologists from Descartes to Kant distinguished things from the ways they are known, while idealists like Berkeley put mind at the foundation of reality and materialists reduced mind to matter. What I am proposing, however, is to unify the distinctions among form, appearance, and substrate, and then to elevate the three-facet distinction itself to an axiom of fundamental ontology Ñ and so to structure ontology itself (in one way) along these lines.
	The structure < Form, Appearance, Substrate > thus defines a special system of ontological categories. For the world is structured importantly, at fundamental joints, by this three-facet distinction. The distinction presupposes that the world includes attributes (of entities), minds (to which entities may appear), and contexts of foundation or origin (from or within which entities may come to be). There may be possible worlds that lack such things, but our world has this much structure, and our ontology and phenomenology are accountable to this three-facet structure of the world. These three categories do not form a sequence of mutually exclusive and collectively exhaustive summum genera of entities, as do the Aristotelian categories (roughly, Substance or Individual, Species, Quality, Quantity, etc). Rather, the categories of Form, Appearance, and Substrate order or rank three fundamental ways an entity in our world is defined: by relation to its form, to its being known or ÒintendedÓ, and to its ground or origin. If you think about it, these categories define three fundamentally important and importantly different areas within the nature of any entity (in a world such as our own). Thus, the entity itself is distributed in its being through these three aspects of form, appearance, and substrate: that is its nature or essence.
	There are other fundamental divisions in the structure of the world. But the division:
		< Form, Appearance, Substrate >, 
marks one crucial ordering in the nature of things. To appreciate its significance, we shall work through some examples below.
	Importantly, the division among form, appearance, and substrate is a division of structure in the nature of an entity Ñ rather than a division among three intrinsically distinct types of property. In principle, the same thing might be part of the appearance, form, and substrate of an entity. The green of a leaf Ñ say, of a California Live Oak tree Ñ is part of its appearance to the human eye, part of its intrinsic form, and part of its evolutionary history (in the role of chorophyll). Thus, the property green plays three different roles in the form, appearance, and substrate of the leaf, and these three facets are themselves defined by the roles played. That is, Form, Appearance, and Substrate are defined by roles played in the nature or essence of an entity.
	An instructive parallel to the three-facet distinction can be drawn in biology: in systematics, the science of diversity among living things (Mayr and Ashlock 1991). Thus, biologists today define a species by principled reference to its character, its observed specimens, and its evolutionary descent. (Exactly how a species is defined in these terms has been vigorously debated; I abstract the terms of debate only.) Imposing our terminology: the form of a species is its genotype, its appearance (to the scientific community) is its phenotype or observable traits (starting with a definitive specimen called its holotype), and its substrate or origin consists in its path of phylogenetic descent from ancestor species. These three aspects of a species are given canonical places in defining the species in modern biological theory, and we may see in this empirical theory something more like a ÒformalÓ division in the nature of all things, not just of evolving species of living things. (N.b. In biological systematics, a ÒcategoryÓ is defined not as a high-level grouping or summum genus, as Aristotle originally used the term, but rather as a rank of taxa or groupings. In the long run I too would define the term ÒcategoryÓ in a more special way, but for present purposes let us mean by the term simply an important group or classification of things.)
	Insofar as biological systematics provides one model of three-facet ontology, we are abstracting or factoring out from the empirical theory of species the formal structure of three facets, which we would apply to any kind of entity at all (in a world such as our own). This kind of abstracting is the proper work of formal ontology, and the three-facet distinction is a formal ontological distinction, applying by hypothesis to any kind of entity whatsoever. The significance of the three-facet distinction lies in the different ways in which something can be defined in its being, in its fundamental nature, by its form, appearance, and substrate.
	Husserl is one systematic philosopher who recognized what we are calling the three facets of an object. The form of an object Husserl called its ÒessenceÓ (Wesen, from Was-sein). The sensible qualities of a material object Husserl called its ÒappearanceÓ (Erscheinung), or more generally its Òway of being givenÓ to consciousness, which aligns with the Òobject as intendedÓ. And the substrate of an object encompasses what Husserl called its ÒhorizonÓ, its Umwelt (surrounding world), and indeed its ontological ÒfoundationÓ, that on which it is ÒfoundedÓ (by Fundierung).  What is unusual in HusserlÕs philosophy is the principle that the essence of any object includes the ways in which it can be known or intended, the ways it is ÒconstitutedÓ in consciousness. It was Husserl who first explicitly defined ÒformalÓ ontology, as specifying categories (Òformal essencesÓ) that apply to different ÒregionsÓ (Òmaterial essencesÓ) such as Nature, Culture, and Consciousness. (The details are drawn in D. W. Smith 1995.) The three-facet distinction belongs to formal ontology in this sense. However, Husserl himself did not join the three facets into the canonical division I am proposing.
	The three-facet distinction, then, is a higher-order formal structure that orders the nature or essence of an entity. Since this structure applies to consciousness itself, we can use the three-facet distinction to look at the ontology of consciousness. But first we must address the distinction generally.

4.	The Three Facets of Diverse Entities

	To see how the three-facet distinction works, and to begin to appreciate its scope, let us apply it to some very different kinds of entities.
	Consider this piece of quartz found in my garden. Its form includes its shape, its color, and its type, quartz. Its appearance includes what it looks like from various angles and under various lighting. And its substrate includes its physical crystalline structure, as well as its geological genesis from great heat and pressure in the crust of the planet Earth.
	Consider now an electron. Its form includes its mass, charge, and spin. Its appearance includes its observable position and momentum, its electron-microscope image, etc. And its substrate includes the matter field (from which it emerges per quantum field theory). So even a basic physical particle has its three facets.
	Now consider this pencil. The form of the pencil is its structure of graphite in wood plus its function in writing and drawing. Its appearance includes what it looks like and what it feels like in my hand in writing. The substrate of the pencil is its origin. It is made of certain materials, including wood, graphite, paint, tin, rubber. Each material has its physical-chemical structure. Moreover, these materials are produced only in specific parts of the world, in specific cultures, their trade following established routes. Furthermore, the substrate of the pencil includes the historical development of writing, writing instruments, and the invention of the pencil. So the pencilÕs substrate includes not only its physical composition (down to quantum structure), but also its cultural genesis.
	Next consider the Tool of the Century: the computer. The International Organization for Standardization has defined what is called the ISO three-schema architecture for database design, distinguishing: a computer program (Òconceptual schemaÓ), its implementation in hardware (plus operating system, etc.) (Òinternal schemaÓ), and the userÕs presentation of what the program does (Òexternal schemaÓ). These three aspects of a computer system are precisely what we are calling its three facets: its form, the program; its substrate, the hardware; and its appearance, the user-interface. This familiar distinction, we now begin to see, reflects a deep ontological distinction in the nature of things far beyond computers.
	Finally, consider a human being, an individual such as Napolean. His appearance is well-known: his facial structure, his small stature, his posture with hand in vest. His form is his individual character as a person, an intentional subject living in a culture in the natural world, his body having various traits. And his substrate is what makes this individual possible: his genetic heritage, his birth on Corsica, the French Revolution and the army in which he developed his power Ñ as well as the wider physical, biological, and cultural conditions of humanity.
	Observe how naturally the three-facet distinction applies to such diverse kinds of entities. The concepts of form and appearance are relatively familiar; the concept of substrate is not. Indeed, notice how wildly different are the things that serve as substrate for different entities: materials or parts from which an object is composed; the field in which a physical particle exists; the genesis of an individual through time; the evolutionary track (or ÒcladeÓ) of a biological species; the cultural history and use of an artifact; the hardware that implements a computer program; the life trajectory of an individual human being; even the cultural genealogy of our values (in NietzscheÕs idiom) and of our language games and other forms of life (in WittgensteinÕs idiom). What these things share, what makes these things play the role of substrate in very different entities, is the form of ontological derivation or emergence (in different ways!) from things more fundamental, the form of ontological foundation or dependence on things in the wider context of the entity. Again, the three-facet distinction belongs to ÒformalÓ ontology.
	Now let us apply the three-facet distinction to Ñ of all things Ñ consciousness itself.

5.	The Three Facets of Consciousness

	An act of consciousness Ñ my experience of thinking, seeing, or doing such-and-such Ñ is an entity with three facets:
(1)	Its form is its structure of intentionality, its being directed from subject toward object through a content or meaning, with inner awareness of itself (ÒapperceptionÓ).
(2)	Its appearance is how I experience it, Òwhat it is likeÓ for me to live or perform this act of consciousness.
(3)	Its substrate is its origin or background in conditions including brain activity, psychological motivation, cultural ideas or practices, and the biological evolution of this form of mind.
The three facets of an act of consciousness are mapped in a diagram in FIGURE 2.

				       structure of intentionality
				    subjectÑactÑcontentÑ>object
					     inner awareness

					 	FORM
						     |

					act of consciousness

					         /	               \

			        SUBSTRATE                     APPEARANCE

     neural-physical-biological conditions	          phenomenological characters of
         psychological conditions				   perception, thought,
             cultural conditions				   emotion, volition ...

FIGURE 2: The Three Facets of an Act of Consciousness

	According to this three-facet ontology, an act of consciousness is distributed in its nature through its form, appearance, and substrate. This is not to say there are three kinds of entities bound together, say, items of brain, meaning, and ÒfeelingÓ. Rather, a particular mental act is one entity with a nature that divides into three fundamentally different aspects or facets. There are systematic relations, including dependencies, among these facets, but that is a further story. First we must appreciate the fundamentally different roles these facets play in defining consciousness. As we bring out these differences in facet, we can carve out the role of phenomenology in understanding mind and its place in the world.

6.	The Structure of Intentionality and Inner Awareness

	I am assuming a basic theory of intentionality (elaborated in Smith and McIntyre 1982.) This account of intentionality draws on a long history, but the main ideas were synthesized adequately first by Husserl. In recent philosophy of mind and cognitive science, Searle (1983) comes closest to this model of intentionality.
	Consciousness occurs in concrete states or events called ÒactsÓ of consciousness: when I see that bird overhead, when I think that Plato was ironic, when I feel angry about the PresidentÕs speech, when I run with the volition to catch a bus, and so on. Such an act of consciousness is intentional, or directed toward something, called its object (the bird, Plato, the speech, my catching the bus). As we say, it is ÒofÓ or ÒaboutÓ that object. The object is prescribed by the content of the act. And the act is experienced or performed by a person, called its subject. This structure is analyzed by laying out cases and marking distinctions among subject, act, content, and object (for detail see Smith and McIntyre 1982). The point to consider here is where this structure plays in the ontology of the act of consciousness, in the three-facetd nature of the act.
	The fundamental structure of intentionality, we assume, is this:

			subject Ñ act Ñ content Ñ> object.

The act is distinct from the object (unless the act is self-referential). The subject is distinct from the act, and from the stream of consciousness in which the act occurs as a transitory part. The content is an idea, image, concept, thought (proposition), volition, etc.: a ÒmeaningÓ which Husserl called noema, updating the ancient Greek term for Òwhat is knownÓ. Importantly, the same object can be ÒintendedÓ through different contents in different acts.
	In practicing phenomenology, when I reflect on an act of consciousness as experienced, I ÒintendÓ the act in a second act of reflection focussed on the first act. In this reflection the first act ÒappearsÓ to the second. Classical phenomenology was much exercised about the best methodology for reflecting on our experience. However we do it, let us assume, I carry out an act of reflection Ñ or introspection Ñ on my own conscious experience. And in phenomenological reflection the intentionality of the given act is part of its ÒappearanceÓ in the reflective act. So the given actÕs intentionality is part of its form, but also part of its appearance in reflection.
	Furthermore, we may directly experience the intentionality of an act of consciousness, without retreating into a reflection upon it. For when I am conscious of something, say in perception, I have a pre-reflective inner awareness of this consciousness-of-something. On this neoclassical view, consciousness is consciousness-of-something and eo ipso consciousness-of-itself.  In inner awareness, then, intentionality ÒappearsÓ to me in having a conscious experience of such-and-such. So intentionality is part of the appearance of the act already in inner awareness. (This form of inner awareness is analyzed in D. W. Smith 1989.)
	By contrast, we do not directly experience (in inner awareness) the substrate of an act of consciousness, notably, its grounding in brain process and cultural history. Nor does the substrate of an experience submit to phenomenological analysis in reflection or introspection. In modern times we all have some knowledge of the fact, empirically discovered and pursued in neuroscience, that what we are thinking, perceiving, or dreaming depends on what is happening in our brains. And in postmodern times we all have some appreciation of the fact, frequently observed in the wake of Marx, Nietzsche, and Freud, that what we think and value depends on longstanding cultural conceptions, assumptions, linguistic practices, and political institutions. But these background conditions must be distinguished from the intentional structure of consciousness itself, thus separating the form and appearance of consciousness from its substrate. (Compare D. W. Smith 1999b on Òbackground ideasÓ in the cultural substrate of intentionality.)

7.	The Ontology of Form and Appearance

	Given the preceding model of intentionality, we can say more about the ontological status of the form and appearance of an entity.
	The form of an entity, we said, consists of its kinds, properties, and relations. These are ÒuniversalsÓ in the traditional sense. I shall not here address the full range of issues about the existence of universals (ably and succinctly assayed by Armstrong 1989, 1997), but a couple of points stand out in present discussion. First, some universals depend for their existence on intentional acts of consciousness and associated cultural practices, though most do not. The property of being a fork, for instance, could not exist unless people had developed the tradition of eating with a utensil of that shape. (See Thomasson 1999, on similar issues of dependence.) Moreover, if I am using a fork to pry open a box, it is not in that context bearing the property of being a fork. Second, a universal is distinct from any concept that represents it. The property of being an electron does not depend for its existence on anyoneÕs having a concept of it; when someone thinks about an electron, the concept ÒelectronÓ is part of the content of the act of thinking, but is distinct from the property of being an electron. And it is universals rather than any associated concepts that make up the form of an entity. Third, a universal is distinct from its instance in a particular entity. Aristotle called such instances ÒaccidentsÓ; Husserl called them ÒmomentsÓ; recent philosophers (following Donald WilliamsÕ usage) call them ÒtropesÓ. Strictly speaking, the form of an entity Ñ in the three-facet distinction Ñ is realized in a complex comprising moments or tropes that are instances of universals. For simplicity, however, in this essay I shall simply speak of an entityÕs form and its constituent kinds, properties, and relations. (Still, the distinction between moments and universals, or ÒidealÓ essences, does important work in an Husserlian philosophy of mind pace D. W. Smith 1995.)
	The appearance of an entity, we said, consists of how it is known or, we may now say, ÒintendedÓ in appropriate acts of consciousness. This talk of ÒhowÓ is ambiguous between the properties that appear or are intended and the contents through which they appear. (Husserl carefully distinguished these: see Ideas I, 1913, ¤42.) When I see that green leaf, for instance, the content ÒgreenÓ in my visual experience is one thing, and the color itself in the leaf is another thing. Science tells us that the color green is dependent not only on the wavelength of the light reflected from the surface of the leaf, but also on the interaction with the observer. Nonetheless, the color in the leaf is distinct from the sensory-conceptual content in my experience. Moreover, as Husserl noted, the same color will ÒlookÓ different under different lighting conditions. The properties in the appearance of the leaf, in its three-facet nature, are distinct from the concepts or sensuous qualities (so-called ÒqualiaÓ) that are part of my visual experience that intends the leaf and presents it as green.
	Clearly, appearance is to be studied in different philosophical disciplines, in phenomenology (addressing its role in intentional consciousness) and in ontology (distinguishing an appearing color itself from the intentional contents that present it).
	Bearing in mind these amplifications of form and appearance in general, we turn to phenomenology as the study of the form and appearance of consciousness.

8.	ÒTranscendentalÓ Phenomenology and the Study of Consciousness

	Consciousness has seemed difficult to study in a disciplined way because it is hard to separate in a disciplined way the different features of consciousness. The distinction between three facets of consciousness helps to define the domains of different disciplines that study consciousness. Purely descriptive phenomenology describes the appearance of consciousness in our own experience: the character of consciousness as we experience it in different types of experience. Analytic (ÒeideticÓ) phenomenology analyzes the form of consciousness: the formal structures of intentionality (already noted in description of our experience). Empirical sciences investigate the substrate of consciousness: the conditions in which it arises in different forms (noted, roughly, in phenomenological analysis). Neuroscience develops the theory of how neural activity gives rise to consciousness in different forms, taking these forms somewhat for granted. Evolutionary biology develops the theory of how different life forms evolved, including animals (and plants?) with the capabilities of consciousness, which begins in sentience and response in low-level organisms (perhaps even in DNA structures themselves if we are to believe some abstractions about the transfer of ÒinformationÓ in very different levels of physical reality). Cultural history develops the theory of how particular forms of consciousness evolved in human history, including the types of conscious and often collective thinking that we call story-telling, philosophy, mathematics, and empirical science.
	It is ontology Ñ formal ontology Ñ that distinguishes not only the three facets of any entity, but the fundamental structures of the world, and so ultimately the place of consciousness in the world, including its relation to brain, species, culture. In this way, ontology defines the parameters of the different disciplines that study consciousness in very different ways.
	In particular, the three-facet distinction in ontology provides a way of defining phenomenology that preserves its original insights without contravening the wonders of todayÕs neuroscience, not to mention evolutionary biology, cosmology, and cultural history. There is no denying the relevance of brain, biology, physics, and culture to consciousness. Yet phenomenology is a different discipline than the empirical natural sciences and the hermeneutic Òhuman sciencesÓ. Husserl labored hard to distinguish phenomenology as a Òrigorous scienceÓ that is distinct from both the natural and cultural sciences. He called this discipline ÒtranscendentalÓ.
	In practice Husserl (1912-13) defined ÒpureÓ or ÒtranscendentalÓ phenomenology as the study of consciousness while bracketing the surrounding world of nature and culture. This methodology Husserl allied with an ontology of distinct essences or ÒregionsÓ called Consciousness, Nature, and Spirit or Culture. To these ÒmaterialÓ essences Husserl applied the ÒformalÓ categories of Individual, Moment or Instance-of-Essence, and State of Affairs. Phenomenology studies intentionality, the central feature in the essence of an act of consciousness (formally an individual). But what is ÒtranscendentalÓ about this phenomenology and attendant ontology?
	Dagfinn F¿llesdal (1982/1969) focusses phenomenology on the ÒmeaningÓ things have for us in intentional experience. Husserl called this meaning or content the ÒnoemaÓ of an act of consciousness. (ÒNoemaÓ is the ancient Greek word for Òwhat is thoughtÓ.) ÒTranscendentalÓ phenomenology then focuses on meaning. Meaning is, on this view, an objective content of intentional experience that can be shared by other acts and, in some ways, expressed in language or in pictures or other media of expression and communication.
	J.N. Mohanty (1985) has expounded transcendental philosophy and phenomenology, looking to Kant, from whom Husserl appropriated the term ÒtranscendentalÓ. In the spirit of Kant, phenomenology would study the basic conceptual and sensory structures of our experience. More precisely, transcendental phenomenology is Òreflection upon consciousness in its object-constituting roleÓ, i.e. intentionality, beginning by Òdelineating the structure of a noemaÓ (xix). What is ÒtranscendentalÓ are the noematic meaning structures through which consciousness intends objects. However, we can no longer hold with Kant that such structures are necessary and a priori (xxix).
	Robert Sokolowski (2000) traces the definition of ÒtranscendentalÓ from Kant back into the Medievals. For the Scholastics, ÒtranscendentalÓ categories apply not to concepts but to beings: the categories of Unity, Being, etc., are ÒtranscendentalÓ because they pertain to absolutely everything. Kant revised this notion, with his Copernican revolution, so that what is ÒtranscendentalÓ are our fundamental concepts: the categories of the understanding, through which alone we can conceive of objects in the world. (Kant explicitly revised the Aristotelian-Scholastic categories by pulling them up from objects into concepts.) Phenomenology then transcends the Scholastic and Kantian conceptions of ÒtranscendentalÓ. As Sokolowski shrewdly observes, ÒTranscendental phenomenology is the mindÕs self-discovery in the presence of intelligible objects.Ó Whence: Òto think about intentionality in all its forms ... is transcendental phenomenology.Ó
	I concur that transcendental phenomenology is the study of intentionality. But I propose to rethink the traditional conceptions of ÒtranscendentalÓ. We may say the three-facet distinction in ontology is itself ÒtranscendentalÓ, radically updating the Medieval notion, insofar as this distinction defines a fundamental formal ontological structure that applies to any entity in our kind of world (from a biological species to a computer system!). Indeed, in terms of the three-facet architecture we can re-define the role of phenomenology in studying the nature of mind.
	The appearance of an act of consciousness is studied in what Husserl called phenomenological description, description of experience as lived. The form of an act of consciousness Ñ the details of its intentional structure Ñ is studied in what Husserl called eidetic analysis of the act, abstracting or factoring out its form or ÒeidosÓ, namely, its being directed from subject to object via content. These are the two stages of method Husserl (1913) used in the practice of Òtranscendental phenomenologyÓ. Now, the substrate of an act of consciousness is studied not by phenomenology, but by the natural sciences (in neuroscience, evolutionary biology, physics) and the cultural sciences (in criticism and history). It is precisely these aspects of substrate that are bracketed in practicing phenomenology.
	What is ÒtranscendentalÓ in phenomenology, then, is its focus on the form and appearance of consciousness, as distinguished from its substrate. But what makes this focus ÒtranscendentalÓ is its marking the formal-ontological distinction among form, appearance, and substrate. For what is ÒtranscendentalÓ in philosophy, in the present scheme, is ÒformalÓ ontology: seeking very basic forms of being. We need not cling to the term ÒtranscendentalÓ; what is important in the study of consciousness is observing the differences among form, appearance, and substrate. If we observe these differences, we should not rule out the relevance of neuroscience and biology for the phenomenological and ontological study of consciousness: empirical studies of brain activity may reinforce or even help to clarify phenomenological observations by showing where in the brain a particular process or quality of consciousness is produced. Still, the analysis of form and appearance in consciousness is the business of phenomenology, informed by ontology. (Compare D. W. Smith 2000b and 2000c.)

9.	ÒNaturalisticÓ Philosophy of Mind and the Study of Consciousness

	The lessons of classical phenomenology are being rediscovered in recent philosophy of mind cum cognitive science, which begins with the metaphysics of naturalism, holding roughly that everything, including mind, is a part of nature and so Ñ turning to epistemology Ñ is to be studied following the methods of the natural sciences. Within this context we need to draw out the implications of the three-facet distinction in formal ontology.
	As noted, it is the discipline of neuroscience, not phenomenology, that must teach us about the inner workings of the brain, how it produces consciousness, how it implements the structure of intentionality Ñ the form of consciousness Ñ in human beings and other terrestrials. When neuroscience-minded philosophers like Patricia Churchland (1986) and Paul Churchland (1995) eliminate the propositional attitudes of belief et al. in favor of neuronal activity, or collapse consciousness into neural flashes, they have limited their view of consciousness to its neural substrate. But there is more in view: there is form and appearance, where intentionality and its subjectivity reside.
	Casting a wider net, we have a growing scientific story of the network of causal interactions within which mental activity occurs, interactions not only within the brain but among brain events and physical events external to the body. This wider causal ecology defines the causal substrate of consciousness. When philosophers like Fred Dretske (1981, 1995) collapse intentionality into the causal flow of physical ÒinformationÓ through environment and organism, they have limited their view of consciousness to its causal-ecological substrate.
	A kindred view of mind is the widespread view that mind is a function, especially a computational function, of the brain. Causal or computational function is a higher-order property of brain activity, of the brainÕs mediation of inputs and outputs of the organism or system. These functional properties of brain belong to the physical, causal substrate of consciousness. Philosophers like Jerry Fodor (1975, 1994) and Daniel Dennett (1991) follow variations on the functionalist theme, as Fodor identifies mental activity with a Òlanguage of thoughtÓ consisting in physical symbols processed in the brain, while Dennett identifies mind with computational brain function viewed from the Òintentional stanceÓ, and consciousness with a particular function (producing Òmultiple draftsÓ of the brainÕs ÒstoryÓ about the world and itself). But functionalism is restricted to a specific view of the causal substrate of consciousness, overlooking the proper analysis of intentionality in the form and appearance of consciousness. (See D. W. Smith 1999a, calling for a wider ontology.)
	The neural and causal grounding of consciousness is not the only sort of condition on which our conscious experience depends. As we have come to recognize, our cultural background also constrains or makes possible, in importantly different ways, the forms of intentionality we may enjoy. We cannot think about ÒnaturalismÓ or ÒracismÓ or laissez faire economics except in an historical context in which other persons, other intentional subjects, have put forth and debated relevant issues. More basically, we cannot think as we do Òin languageÓ unless we have acquired a language, such as English. (See D. W. Smith 1999b on Òbackground ideasÓ.) Cultural preconditions, then, define a distinct region of the substrate of an act of consciousness. When philosophers like Richard Rorty (1979) reduce consciousness to philosophical ÒconversationsÓ following Descartes, they restrict their view to the cultural substrate of our philosophical self-consciousness. But there is more to consciousness than what we say about it, even if our discourse shapes our awareness of our own experience. The form and appearance of our experience is distinct from its cultural background.
	Still another kind of precondition of our human forms of intentionality is our biological heritage. Here is where the evolutionary biologistÕs point takes hold. I quoted Edward O. Wilson (1998) earlier, where I intimated that in the study of consciousness, physical and biological theory need to be developed in relation to phenomenology and ontology. Consider the role of biological evolution. The human organism Ñ its nervous system, indeed its genome or overall genetic footprint Ñ evolved in the natural environment of the planet Earth, in the planetary system of the star we call the sun, in this universe which has developed over some 12 billion years since the Big Bang. These natural conditions are preconditions for our forms of consciousness: for intentionality in the form of visual perception (by two eyes two inches apart on the front of a head), emotion (desire, fear, anger), cognition or thought (about water or fire or Plato), or volition (to run, using two primate legs rather than two differently-advantaged lizardly-aviary ÒlegsÓ). Wilson is right that, in some sense, natural science will ÒexplainÓ mind, consciousness, even the arts and humanities, even the natural sciences themselves as disciplines that have evolved in human cultures in the blink of cosmic time here on Earth. And philosophers such as Ruth Millikan (1984) and Daniel Dennett (1991, Chapter 7) are right that, in some sense, intentionality and human consciousness will be ÒexplainedÓ by principles of biological evolution. However, these kinds of studies of consciousness are limited to the biological substrate of consciousness. The intentional-subjective form and appearance of consciousness must be ÒexplainedÓ in different ways, in a phenomenological ontology that observes the three facets of consciousness.
	The form and appearance of consciousness, featuring structures of intentionality, are simply different from its substrate, physical and cultural. This was the force of HusserlÕs long argument in the Crisis (1935-38); I resituate the claim, however, in terms of the three-facet distinction in categorial ontology. In recent philosophy of mind, John Searle (1992) has sharply separated the irreducibly subjective properties of consciousness and intentionality from their ÒbackgroundÓ of neural capacities, arguing thus against the prevailing physical-computational models of mind in cognitive science; again, I would resituate these differences within the three-facet ontology.
	Here I want to stress that the form and appearance of consciousness are to be studied in their own right in phenomenology cum ontology, whereas the substrate of consciousness is to be studied in relevant disciplines in the physical, neural, biological, and cultural sciences. Given the three-facet distinction, we see what is wrong with the familiar ontological proposals in recent philosophy of mind, from reductive to eliminative materialism, from functionalism to computationalism to causal externalism to evolutionary psychosociobiology. These ÒnaturalisticÓ theories are all looking for intentionality, qualia, subjectivity in the wrong places, in parts of the substrate of consciousness, rather than its form and appearance.

10.	The Ontology of Substrate

	To understand more clearly what counts as the substrate of consciousness, we need to address the ontological structure of substrate in general.
	Every entity, we assume, has a substrate, initially defined as its ÒfoundationÓ or ÒoriginÓ. But different entities may be founded or originated in very different ways, as our examples showed, and this fact may distract us from the basic ontological form involved. Fundamentally, the substrate of an entity consists of what it depends on for its existence, where A depends (ontologically) on B if and only if A could not exist unless B existed. It is this notion of dependence that we must now look into.
	For Aristotle, a quality in a substance cannot exist apart from the substance. Expanding on this notion, Husserl defined a dependent part as a part that cannot exist outside the whole, so that the part Òrequires foundationÓ by the whole. But we need to separate part and dependence, as something may be dependent on an entity of which it is not a part. Thus, from HusserlÕs complicated scheme, we may distill the following definition of dependence:

A depends or is founded on B if and only if A could not by essence exist unless B exists, i.e., necessarily, by virtue of essence, A exists only if B exists.

We can also say that A is grounded on B, or B is the/a ground of A. While Husserl often used the term ÒfoundationÓ (Fundierung) instead of ÒdependenceÓ (UnselbstŠndigkeit), I prefer to speak of dependence because the term ÒfoundedÓ suggests one-way dependence yet two things may each depend on the other (neither could exist without the other).
	There are different kinds of dependence: physical, biological, cultural, etc. But, on this analysis, the form of dependence is always the same: A could not exist unless B existed. Husserl adds the qualification Òby essenceÓ, and Kit Fine (1995) further explicates dependence in terms of his own conception of essence. However, there are different kinds of conditions on which something can depend: causal physical circumstances, evolutionary biological circumstances, social cultural circumstances, etc. Moreover, there seem to be different kinds of ÒcouldsÓ, different modes of possibility or necessity: what is physically necessary, biologically necessary, psychologically necessary, legally necessary, etc. On the Husserl-Fine analysis, these differences may be attributed to essence: Ònecessarily, if A has essence EA and B has essence EB then A exists only if B existsÓ. These details of essence and necessity lie beyond the scope of the present study; for present purposes let us assume the basic account of dependence as defined above. (Remember that ÔessenceÕ in Husserlian idiom means what something is, not what it is necessarily or ÒessentiallyÓ.)
	Many of the central problems of metaphysics involve ontological dependence. The in re theory of universals holds, with Aristotle, that a quality can exist only if instantiated in an individual (or Òprimary substanceÓ). Causation may be analyzed in terms of dependence, as: A is caused by B just in case A is physically dependent on B, or it is causally necessary that if B occurs then A occurs. Classical idealism holds with Berkeley, and realism denies, that material objects depend on their being perceived or otherwise projected by minds: that is to say, a material object, by its essence, can exist only if perceived or otherwise intended in consciousness. KantÕs transcendenal idealism holds that certain conceptual categories and certain forms of sensibility are the Ònecessary conditions of the possibilityÓ of our knowledge of the empirical world around us. I would reconstrue this epistemological claim in the idiom of ontological foundation: our familiar forms of intentionality, or knowledge of objects in the world around us, could not occur unless we had acquired or inherited a certain repertoire of conceptual and sensory structures, that is, our familiar forms of intentionality depend or are founded on these conceptual-sensory structures. More recent philosophers Ñ from Husserl (1913) and Heidegger (1927, as interpreted in Dreyfus 1991) and Wittgenstein (1953) to John Searle (1983, 1993) Ñ have stressed the background social practices that condition our experience. Searle posits a ÒbackgroundÓ of acquired skills or practical capacities (realized in neural structure) on which our intentional states rest; as Searle puts it, these capacities ÒenableÓ our intentional states to represent what they do. I would explicate this enablement in the idiom of ontological foundation: our intentional states could not represent or ÒintendÓ what they do, our intentional relations could not obtain, unless these capacities existed in our ÒbackgroundÓ. (Compare D. W. Smith 1989, Chapter VI, and 1999b.)
	An influential view in recent philosophy of mind and cognitive science holds that mental states are ÒsupervenientÓ on physical states of the brain (Davidson 1970 and Kim 1994, 1998). While supervenience has been variously defined, the issues at stake are covariance and dependence: the mental varies with the physical so that every mental state occurs along with an appropriate brain state and could not occur unless such a brain state occurred. The core definition is, I think, best formulated as a doctrine of ontological dependence: every mental state is said to depend on some brain state in such a way that mental state types covary with physical state types.
	David Lewis (1986) uses supervenience in the metaphysics of possible worlds. David Armstrong (1997) holds that a state of affairs (that an individual has a property or that two individuals stand in a relation) supervenes on its constituents (the individuals and universals involved). But Armstrong holds that supervenience brings into the world no new entities beyond those on which the supervenient ride: supervenience offers an Òontological free lunchÓ, as Armstrong has put it. Thus, a state of affairs would not be an entity in addition to the individuals and universals of which it is composed. And if mental activity supervenes on brain activity, there would be no new, distinctly mental entities beyond the physical entities, the brain states, on which mind supervenes. In the theory of ontological dependence outlined above, however, there is no free lunch. It does not follow from the above definition of dependence that A is not another entity beyond B. Quite to the contrary, in the cases that concern us, A and B are distinct entities between which a relation of dependence obtains, so that  A can exist only if B exists.
	An important but neglected form of dependence is one I discern in Alfred North WhiteheadÕs ontology. In WhiteheadÕs Process and Reality (1928), as commonly interpreted, the Aristotelian notion of substance, or enduring material object, is replaced by the notion of process (see Rescher 1996). However, Whitehead himself distinguished what I would call ÒontologicalÓ becoming from temporal becoming. Every actual entity, Whitehead maintains, is constituted by its relations (of ÒprehensionÓ) to other actual entities in its process of ÒbecomingÓ, or ÒconcrescenceÓ. But Whitehead distinguishes two types of ÒfluxÓ: (a) the temporal flux by which a new entity emerges from others in the ÒtransitionÓ to the novel entity, and (b) the ÒconcrescenceÓ of one entity formed out of many on which it depends. It is this latter notion I call ontological becoming. (See D. W. Smith 2000a.) WhiteheadÕs conception of concrescence I want to cast as a very fundamental form of dependence: one actual entity depends on a number of other entities in its existence, its Òinternal constitutionÓ. Indeed, the doctrine of logical atomism in Russell and Wittgenstein affords another instance of ontological becoming: a state of affairs is ÒlogicallyÓ formed out of individuals and properties or relations they bear. This complex entity depends ontologically on its constituents. But these are not like automobile parts, which are put together in a spatiotemporal relation to make the whole. A state of affairs is rather put together by ÒlogicalÓ relations of property-instantiation. Whitehead did not adopt RussellÕs ÒlogicalÓ atomism; instead, he elaborated an ÒatomismÓ where entities are put together by another kind of bond called ÒprehensionÓ.
	Thus, pace Whitehead, the ultimate substrate of any ÒactualÓ entity or occasion, including an act of consciousness, is its ÒdeepÓ ontological structure. In this way phenomenological structure rests on ontological structure. (This, on the model adumbrated in D. W. Smith 2000a). 

11.	The Substrate of Consciousness

	The substrate of consciousness is that aspect of an act of consciousness which consists not in how it is intentionally directed (its form), nor in how it feels to its subject in inner awareness (its appearance), but in how it comes to be, how it originates ontologically, how it depends or is founded ontologically on various conditions in the surrounding world. In the normal course of events, I could not see or think or will what I do, in a given act of consciousness, unless certain background conditions obtained. That is, the act could not be directed as it is Ñ from subject through content to object, with an inner awareness of the act built in Ñ unless these background conditions obtained. The substrate of the act consists in its dependence upon these background conditions. This pattern of relations among the substrate, form, and appearance of an act of consciousness may be depicted in the following diagram (where the T-bar stands for ontological dependence and the three facets are given a slightly different look):

							     F O R M

	background conditions  |Ñ  	<  subject Ñ act Ñ content ÑÑÑÑÑ> object  >
								|
							awareness-of-act
	    SUBSTRATE				APPEARANCE

	As noted earlier, an act of consciousness may depend in different ways on a wide variety of things in the world. But we seek order in this variety. It seems that there are certain kinds of background conditions on which consciousness depends in systematically different ways. Thus, I propose, the substrate of an act divides into its patterns of dependence upon:
a)	the psychological or personal history of the subject, which conditions his or her experience, making it more or less likely that she will see or think or feel or do things as she does;
b)	the cultural context or social history of the subject, which conditions his or her consciousness, affording her relevent concepts, values, and Òforms of lifeÓ including language;
c)	the neural activity in the subjectÕs brain, including processes of computation in the neural network, which make possible this form of consciousness, and which in turn depends on appropriate physical and chemical processes;
d)	the biological processes of evolution that allow the emergence of this form of consciousness, which thus condition the consciousness in still another way, and which in turn depend on the cosmological processes by which life itself evolved.
I believe these are the most basic, and fundamentally different, realms of being on which consciousness depends, in different ways. One might argue for a different organization of the substrate of consciousness, but my aim is first to organize the nature of an act of consciousness into form, appearance, and substrate, and then to look into the organization of the substrate. In fact, the above division of substrate Ñ into psychological, cultural, neural, and evolutionary conditions of dependence Ñ reflects a fundamental division of labor among the disciplines that have studied mind over the past century or two. Each of these four domains of study has developed as a rich and even revolutionary field: psychology, from psychoanalysis to cognitive science; cultural analysis, from social science to humanistic critical theory; neuroscience, becoming its own science in recent decades; evolutionary biology, again gaining salience in recent decades. If you will, this fourfold division in the substrate of consciousness is simply a classification of the chief empirical results, or Òmaterial ontologiesÓ, in the theory of mind. But these four areas in theory of mind are framed, here, by a distinction in formal ontology: the three-facet structure of form, appearance, and substrate, applying this structure to consciousness.
	The philosophy of mind in recent decades has divided into theories that stress particular features of mind which I would systematize in the above division of the substrate of consciousness. Various naturalistic theories, we noted, stress causal, computational, neural, or biological conditions of those mental states we experience as consciousness. Culturalistic theories stress the origins of mental life in social conditions and human history. And psychologistic theories stress the contingent psychological origins of experience, rather than (as Husserl demanded) their meaning, or logically formed intentional content. Phenomenological theories have, by contrast, distanced themselves here and there from precisely these tendencies. Now, all these dialectical cross-currents fall into place if we adopt a systematic ontology of the nature of consciousness: first distinguishing its form, appearance, and substrate, and then distinguishing these four regions of dependence within its substrate.
	This diverse structure of the nature of mind comes into relief only as we look systematically at form, appearance, and substrate. And the special roles of ecological conditions of consciousness come to prominence only when we bring out the role of ontological dependence in the substrate of consciousness. We must not, then, identify the nature of consciousness with one of these types of conditions in its substrate, with brain, or computational function, or causal role, or cultural role, or evolutionary role. To depend on something, even deeply and fundamentally, is not to be identical with it.

12.	The Return of Phenomenology

	Consciousness is indeed what makes the mind-body problem difficult, when we look to the results of natural science Ñ or indeed cultural theory. It is also what makes life worth living and philosophy, since Descartes and Kant and Husserl, so exciting.
	We will not fully ÒunderstandÓ consciousness until we see how it fits into the structure of the world defined by quantum physics, evolutionary biology, cultural history, and even cosmology. But our understanding of consciousness must begin with our own experience, as Descartes began to see. Our understanding will begin with the structure of consciousness analyzed in phenomenology, and will go on to integrate the results of phenomenology with those of natural science and cultural analysis in a unified world-picture framed by basic ontology.
	Phenomenology will elaborate (part of) the form of consciousness in the structure of intentionality, and will detail the appearance of consciousness in different forms of experience, including our inner awareness of experience. These analyses of form and appearance will interweave with logic, mathematics, computer science, and formal ontology, in analyses of forms of various things including consciousness. This complex of analyses will ultimately tie into analyses of the substrate of consciousness, comprising conditions under which the extant forms of experience are realized, conditions mapped out by the empirical natural sciences and the social or cultural sciences. And the structure of the world in which consciousness and its empirical background conditions obtain will be framed by basic formal ontology.
	What is hard about understanding consciousness is getting our mind around all these different kinds of structure while keeping straight their differences. We do this as we delimit phenomenology and its kindred ontology.

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