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Dualism, Consciousness and Self-Identity
in Descartes and Sartre

by Richard Grego


Jean Paul Sartre's existentialist phenomenology was in many ways an attempt to eliminate Rene Descartes' dualism with respect to consciousness and self-identity. As illustrative of the 'post-modern' intellectual-cultural ethos that they did much to configure, Sartre's ideas represent a radical transformation of Descartes' 'modern' conception of the ego. However, a close examination of Descartes' and Sartre's ideas in comparative perspective suggests that this transformation involves more of an inversion of Cartesian dualism than the simple elimination of it.

This essay will compare perspectives on the ontological structure of consciousness in the respective writings of Descartes and Sartre. Specifically, it will examine their views on the relationship between self-awareness and conscious life. It will focus on the critical discussion of this relationship in Descartes' Discourse on Method, Meditations, and Principles of Philosophy and in Sartre's Transcendence of the Ego and Being and Nothingness. Since each considered the issue of self-identity and consciousness to be foundational to his own thought, examining their contrasting views on this issue may reveal much about how basic assumptions regarding the 'ego' or 'self' have changed since the inauguration of modernity four centuries ago. Moreover, their contrasting ideas may also say much about the differing intellectual/ cultural contexts from which these ideas have emerged.

Descartes' concept of a self-aware ego, and Sartre's notion of an ego-less self-awareness, reflect contrasting intellectual/ cultural paradigms in the history of western civilization. Descartes' self-concept reflects modernity's idea of self-identity and — insofar as Sartre's self-concept reflects the nature of the post-modern self — exploring the similarities and contrasts between Descartes and Sartre illustrates how self-identity in the postmodern milieu can be understood paradoxically as both the culmination of modernism and as a reaction against it. For, though Sartre's concept of the ego differed from that of Descartes in many respects, Sartre (like Husserl and other phenomenologist) still took Descartes' Cogito as a philosophical point of departure. Sartre's thinking on this issue was thus heavily influenced by Descartes and can be interpreted on different levels as (however unsuccessfully) both confirmation of and rejection of the Cartesian legacy.


Basic similarities are evident, for example, in both thinker's philosophies of 'mind'. Both view mental activity as essentially non-material. While Descartes grounds his non-material mind in the spiritual 'substance' of God, and Sartre grounds his non-material consciousness in the radical 'freedom' of 'nothingness', both still view conscious experience as fundamentally different from the physical or extended reality that it 'inhabits'. Consequently, both also view mind or conscious experience as one aspect of a dualistic reality. Though Sartre's phenomenology was an attempt to overcome Cartesian dualism and there are profound differences between them regarding the nature of dualism, both envision reality as constituted by a thinking, free, self-aware subject in ontological opposition to a material, static, and unconscious object. Descartes and Sartre both also agree that subjective consciousness is a uniquely human activity. Although Descartes includes God as conscious (actually as the source of consciousness), both concur that the objective or factual reality 'outside' of human subjectivity does not and cannot 'think' in a conscious sense. Most importantly perhaps, both view the capacity for self-awareness as essential to conscious experience. The larger ramifications of this are ultimately different for each, but both agree that this capacity grounds and delimits the scope of human understanding.

Thus Descartes uses his own capacity for self-awareness to arrive at the Cogito:

'But immediately I noticed that while I was endeavoring in this way to think everything false, it was necessary that I, who was thinking, was something. And observing that this truth, 'I am thinking, therefore I exist' was so firm and so sure that... I decided to accept it without scruple as the first principle of the philosophy I was seeking' (DM, 36).

Essential to this experience of consciousness is the 'I' that does the 'thinking' — A 'self' that remains a persistent and substantial locus of conscious awareness. This self is the 'substance' constituting thought. 'From this I knew that I was a substance whose whole nature is to think' (DM, 36).

Yet the Cartesian 'I' also seems to exist in a sense that somehow transcends its own thoughts: 'I' consist of my thoughts, but also collect, possess, and witness them. Although thinking constitutes my 'nature', 'I' seem to also exist in some critically detached way that simultaneously transcends the very thoughts that I am observing. I exist independently from my thoughts as an ego that contains them.

This Cartesian ego (which has plagued philosophy of mind ever since) is the ontological excrescence that Sartre considers the source of a false dualism — and that he attempts to rid philosophy of. He is successful in eliminating the Cartesian ego, but not dualism. In fact, his attempt to eradicate Cartesian dualism arguably results in a more thoroughgoing Sartrean dualism.

Though, like Descartes, Sartre posits self-awareness as essential to consciousness, he also rejects Descartes' idea of a transcendent ego reflecting somehow on its own thinking. 'Of course consciousness can know and know itself', Sartre writes, 'But it is in itself something other than a knowledge turned back on itself' (BN, LXI) Although consciousness exists in a very definitive sense and can be self-aware, it does not consist of thoughts contained in or belonging to an 'I' or ego in the Cartesian sense. Since 'existence precedes essence', thinking or consciousness can have no 'substance' or 'nature'. Consciousness for Sartre is radically 'free' or unconditioned mental activity without any transcendent 'ego' from which it emanates. The subjective experience or sense of a 'self' IS this activity and cannot have any existence apart from this activity. (BN, LXV-LXVI)

Therefore, as Sartre states in The Transcendence of the Ego: '... the consciousness that says 'I think' [in Descartes' Cogito] is precisely not the consciousness that thinks... There was no 'I' in the unreflecting consciousness' (45-46). Sartre removes the Cartesian ego from consciousness via the concept of 'intentionality': Conscious activity consists solely in the positing or apprehension of its objects. It is a subjective directedness toward the objective world external to itself. It is aware of its activity, but not as any activity issuing or deriving from an ego that transcends this activity. Consciousness is only conscious of itself as 'consciousness-of' something. (BN, LXI-LXII)

Thus Sartre conceives of subjective consciousness as primarily a 'pre-reflective' or dynamic process. When one is actively engaged in an experience, the 'I' or ego does not appear and one is not aware of one's 'self': 'When I run after a streetcar... there is no 'I'. There is only consciousness of the street-car-having-to-be-overtaken'. (TE, 49) It is only during 'reflective' mental activity (thinking about experience in retrospect — objectively) that consciousness posits its prior thinking as unified by or issuing from a transcendent ego. However, this ego is itself just another object external to the subjective consciousness that posits it. There is no transcendent or objective ego to which consciousness belongs or from which consciousness derives. In fact, the opposite is true: 'For most philosophers, the ego is an inhabitant of consciousness... We would like to show that the ego is neither formally nor materially within consciousness: it is outside, in the world' (TE,1).

For Descartes in contrast, the self or ego, which DOES exist in direct relation to consciousness, can reflect upon itself as it thinks. The ontological structure of Cartesian consciousness (following the Scholastic tradition) is configured by the relationship between mental 'substance' which is characterized by its primary essence or 'attribute', which is thought ('To each substance there belongs one principle attribute; in the case of mind, this is thought... ' (PP, 177). Thinking belongs to a mind. Since the mind or ego exists in transcendent relationship to its thoughts, it can direct these thoughts back upon itself or upon its prior thoughts.

'But what then am I? A thing that thinks. What is that? A thing that doubts, understands, affirms, denies, is willing, and also imagines and has sensory perceptions. This is a considerable list, if everything on I belongs to me. But does it?... The fact that it is I who am doubting and understanding and willing is so evident that I see no way of making it any clearer' (MP, 83).


Sartre's rejection of this Cartesian ego, and his idea instead of an intentional consciousness, leads to an attempted (and unsuccessful) rejection of Descartes' subject/ object dichotomy between the conscious ego and the unconscious world. Descartes' idea of consciousness is predicated upon the assumption that the thinking subject is fundamentally different from the objective physical world — that 'I exist' (as mind) and 'there exist things distinct from myself' (physical or extended objects). Insofar as the human mind participates in the Divine mind, in fact, the subjective conscious 'soul' remains separate from the objective 'fallen' physical world (PP, 182-189). (For the former Jesuit student, the 'City of God' is distinct from the 'City of man'). 'I exist, I find in my mind the idea of God who must — by his very concept — exist; God being good, will not deceive me in my clear and distinct ideas. Hence my belief in an external world must be true idea' (PP, 189).

Sartre, on the other hand, deliberately tries to eradicate any distinction between the ego and its world. Though he accomplishes this, he does not overcome the dualism that separates consciousness and its reality. To effect a fundamental interdependence between conscious experience and the world that it apprehends, Sartre empties consciousness of substance entirely. He asserts that, not only is intentional mental activity in no way the 'attribute' of any mental 'substance', but that it is also nothing more than an insubstantial 'striving toward' its objects of apprehension. In itself it is 'nothing' — insubstantial and possessing no attributes. It is an empty and insubstantial activity. A pure subjectivity through which objectivity is revealed. 'All consciousness ... transcends itself in order to reach its object' and 'Nothing is the cause of consciousness' (BN, LI-LVI). So in this sense, intentional consciousness and the objective world are co-extensive: Consciousness needs its objects in order to exist, such as it does, because it is nothing in itself without them. The objective world needs consciousness in order to be revealed as existing.

Thus Sartre tries unsuccessfully to unify subjective consciousness and the objective world via the empty or perpetually transcendent activity of intentionality. However, the very activity through which this union is attempted obviates its own possibility. The two 'worlds' cannot be reconciled. The subjective nihility of consciousness, opposed to the object substance of its world, makes any such union impossible. The objective world of factual reality simply 'is' in the most concrete sense. Subjective consciousness perpetually 'is not what it is and is what it is not' (BN, LXI)

So while Sartre attempts to eliminate subject/ object dualism by making the conscious 'self' interdependent with its world — but actually seems to make the conscious subject less existent than or ontologically subsequent to the objects it reveals, Descartes posits a dualism in which the thinking subject is more existent than or ontologically prior to the worldly objects that it perceives. The Cartesian ego, via the Cogito, first establishes the indubitable truth of its own existence, which is its most 'clear and distinct' knowledge. From this self-certainty it then (with the assistance of God, whose 'substance' is intrinsic to its own) deduces the existence of an objective external world — whose 'substance' is physical 'extension', as opposed to the thinking substance of the ego. The existence of an objective world is only established after the existence of the thinking subject is established. Moreover, this subjective ego does not need the objective extended world in order to establish its own existence. It exists, in a sense, as a self-contained entity. A non-physical soul. Grounded securely on the self-sustaining existence of God, its existence is not contingent upon the world. He writes:

'On one hand I have a clear and distinct idea of myself, insofar as I am simply a non-extended thing; and on the other hand I have a distinct idea of the body, insofar as this is simply an-extended non-thinking thing. And accordingly it is certain that I am really distinct from my body and can live without it' (MP, 114).

In contradistinction, for Sartre the conscious subject is utterly contingent (so much so, in fact, that that contingency almost seems like the 'substance' of Sartre's consciousness, though his characterization of consciousness as 'free' or as 'nothingness' would preclude this possibility). It could not exist without its objects since the intentional activity that constitutes it occurs only as a 'striving toward' these objects. It is therefore less existent than the substantial 'facticity' or concrete existence of the objective world.


For this reason Sartre regards the mental act of imagination — integral to intentionality — as essential to consciousness. Imagination is the aspect of conscious experience in and through which possibilities are projected. The projecting of possibilities is the very activity by which intentional consciousness engages the world of objective facticity. Unlike the determined and static character of the factual world (called 'being-in-itself'), conscious activity (called 'being-for-itself') is perpetually and relentlessly moving — striving toward and beyond this world. It is perpetually transcending all objective facticity by projecting possibilities each and every moment. Consciousness, or being-for-itself, IS this perpetual movement , which is 'freedom'.

Because of its imaginative character, consciousness or being-for-itself is radically free — unlike the determined world of being-in-itself, toward which it projects but with which it can never attain consummation. The freedom of being-for-itself to project possibilities for being-in-itself is what makes being-for-itself 'nothing' in itself and irreconcilable with being-in-itself. Since being-in-itself is precisely 'just what it is' (determined), and being-for-itself is always 'beyond what it is' (free), the freedom of consciousness perpetually negates the very reality that it is contingent upon. Freedom, as 'the ability of consciousness to destroy, ignore, or go beyond its objects' via imagination, thus separates consciousness from its world. Yet consciousness is this freedom (BN, 25).

For Descartes however, neither imagination nor freedom are as significant or as ontologically problematic. He views imagination as an essentially superfluous dimension of experience, connected as it is to the senses and the extended substance of the physical body. A product of the visceral emotions rather than of rational thought, it is not essential to mind or consciousness.

'I consider this power of imagining which is in me, differing as it does from the power of understanding, is not a necessary constituent of my own essence, that is of my mind. For if I lacked it, I should undoubtedly remain as I now am' (MP, 111).

Imagination is thus relegated to the level of sensory knowledge — which is neither true knowledge nor thinking in the essential sense. Imagination for Descartes is therefore also not connected to freedom in the way that it is for Sartre. Freedom for Descartes is integral, instead, to mental autonomy of an exclusively rational nature. Only this dimension of consciousness qualifies as 'thinking' and hence, as essential to consciousness (MP, 112).

The contrasts between Descartes' and Sartre's notions of imagination — and hence, of freedom — perhaps illustrate most effectively the basic distinction between their respective conceptions of dualism and self-identity. Sartre conceives of consciousness as subjective freedom, which is nothingness, while Descartes views consciousness as an extension of the objective being of God. For Sartre, consciousness is freedom as being-for-itself, which is 'condemned' to perpetually project toward and beyond the the determined being-in-itself upon which it is contingent. However, the ontological opposition of being-for-itself and being-in-itself makes a being-for-itself-being-in-itself union impossible, and consciousness must always for this reason, negate or nihilate the very objects with which it seeks consummation.

One of these objects turns out to be consciousness itself. Since the objective ego becomes becomes being-in-itself by the very act of reflecting upon it, it remains external to the subjective being-for-itself in pre-reflective consciousness. By positing and identifying with its ego, consciousness attempts to become a being-for-itself-in-itself. It attempts to give its freedom substance while still remaining unconditioned and free. It tries to give its nothingness valid being. It tries to objectify its subjectivity. This is impossible however, and the free subjectivity from which conscious experience emerges remains alienated from any objective self-identity.

This is not the case with Descartes. Though consciousness and the external world are indeed distinct, consciousness still remains the locus of self-identity. Since it participates in the absolute being of God, the thinking substance of consciousness gives the ego concrete being. 'My' existence as a thinking subject is identical with my self-identity. This is the 'clear and distinct' self-evident character of conscious experience. Consciousness for Descartes is thus the opposite of nothingness — whereas for Sartre 'consciousness is freedom is nothingness'.


Thus, far from eradicating Cartesian dualism by de-substantializing the ego, Sartre actually intensified this dualism and perpetuated much of the Cartesian legacy that he sought to supplant. For, although Descartes separated the ego from the world to a relatively greater degree than many of his classical and medieval predecessors, it nonetheless retained a place — however precarious — in the cosmic continuum encompassing all reality. ('I realize that I am, as it were, something intermediate between God and nothingness, or between being and non-being', MP, 99.)

However, Sartre not only separated consciousness from the world absolutely and inalterably via the being-for-itself/ being-in-itself dichotomy, but he further separated self-identity from its own originating ground by making the free subjective 'nothingness' of pre-reflective consciousness irreconcilable with the objective ego of reflective consciousness. Unlike the Cartesian ego, with a place in the universe, the Sartrean consciousness is nowhere. Thus the modernity's Cartesian dualism appears to have culminated in post-modernity's existential alienation. Far from being overcome, the problems associated with Cartesian dualism are more prominent than ever.

In this way Sartre's inversion of the the Descartes' Cogito represents one of the most problematic and ironic philosophical developments in the recent history of ideas. In a post-modern culture where issues related to individual freedom, personal isolation, social alienation, etc, are increasingly prominent in public life, this development exemplifies what may be an important transition in western civilization generally. Where future philosophers may take this trend remains as open a prospect as Sartrean freedom itself.


Descartes, Rene. Selected Philosophical Writings. J. Cottingham. trans. (Cambridge: University Press) 1988

Sartre, J.P. Being and Nothingness. H. Barnes, trans. (New York: Philosophical Library) 1956

Sartre, J.P. Transcendence of the Ego. F. Williams, trans. (New York: Octagon Books) 1972

© Richard Grego 2007

Dr. Richard Grego
Associate Professor
Department of Philosophy and Culture
Daytona Beach Community College