Sunday, 7 April 2019

Neuroethics and Cartesian Metaphysics: An Enduring and Inconvenient Marriage

by Denis Larrivee & Luis Echarte

Introduction
Philosophical roots of modern neuroethical praxis and neuroscience are greatly influenced by the metaphysical approach to natural reality developed by Descartes. Seen in contemporary trends like cognitive ontology, neuroessentialism, posthumanism, and extended mind theory these varying approaches reflect emphases on Cartesian philosophical attempts to come to grips with the empirical reality of the phenomenal subject and its fundamental, i.e., metaphysical, relation to natural reality.  

1. The Cartesian Legacy in Conceptions of Natural Reality.
A. The French Philosopher’s Novelty and Enduring Influence in the Understanding of the Natural World. 
Heidegger points out that Descartes effected a fundamental change in the understanding of natural reality by taking the ground of reality to be the autonomous I (Onishi, 2011). Before Descartes, natural reality was conceived as individuated, composed of entities or holisms that possessed unique properties distinguishing them from all other entities (Esfeld, 2004; Freddosso, 2010; Marion, 2007). Descartes’ introduction of the divided and autonomous I, distinct from the individual though Descartes attempted to link the subject to a bodily location in the pineal gland was consistent with his understanding of efficient causality that attributed to the ‘mental’ I a causal origin capable of effecting change. This exteriorized notion of causality initiated a scientific revolution in succeeding centuries that explored compositional and contiguous relations in natural phenomena and developed an empiricist epistemology that interpreted nature as a product of more and still more elementary components, which could exert direct, causal influences on one another. Nonetheless, the introduction of the segregated I created an enduring legacy in dualistic approaches to cognition.

B. Connecting the Cartesian Interpretation of Natural Reality with Metaethics in Modern Neuroethical Praxis
Cartesian compositional and dualistic conceptions of nature, in concert with their subsequent evolution, yet influence the understanding of the personal subject, cognition, neuroscience, and neuroethical praxis. Cartesian influence is most directly seen in the metaethical understanding of the personal subject and its manner of association with the physical reality of the individual, as interpreted by neuroscience. Because the personal subject constitutes a locus of value, the material reality of the body acquires value through its association with the individual subject. In general three modern metaethical variants trace their interpretation to Cartesian influence on the manner of this association, 1) the autonomy of the personal subject from the physical structure of the brain/body, seen, e.g., in posthumanism (Bostrom, 2005), 2) a tenuous and amorphous link, initially proposed by John Locke in his appropriation of the Cartesian subject, now influencing extended mind theories (Levy 2011), and 3) a direct mapping of the subject onto the material form of the brain/body, seen, for example, in neuroessentialism and cognitive ontology (Reiner, 2011). In posthumanism, the emancipatory and liberated I/ego validates plastic alteration of the material, neural architecture. In extended mind theory, ethical parity notions between the external and brain-based mind are used to justify neuromodulation of the brain. In neuroessentialism/cognitive ontology the subject is situated only to the brain or its parts which thereby acquire normative priority with respect to the body or remainder of the brain.

2. Unresolved Paradoxes Introduced by Cartesian Metaphysics
A. The Paradox of Hierarchy and Order
Cartesian emphasis on causal relations that are solely external, efficient interactions leaves unanswered the question of organizational order and why only certain arrangements are selected. Indeed, the explanation of preferred orders cannot be explained by efficient causal relations alone, e.g., as in interlevel interactions, but necessitates the invocation of a formal causal order that can account for such organization, like the case of intrasystemic feedback (Bechtel, 2017). In its absence features like neural integration are unexplained, leaving, unintegrated functionalist accounts of neural network operation to explicate operation. Such explanations, for example, are offered in cognitive ontology.

B. The Paradox of the Self: The Dynamic Unity of the Individual
The Cartesian emphasis on the isolated ego leaves unaddressed the necessity of the self as a principle of coordinated and dynamic unity. Without an overall unity that is subject to guidance it is not possible to engage in coordinated performance. This unity must emerge from within the individual, and not outside the topological perimeter of the body, that is, it is through the unique structural/operational order of the body and neural architecture that the self emerges (Mossio and Moreno, 2015). Extended mind, by contrast, presupposes that the self is emancipated from the body, lacking a common neural and biological core.

C. The Paradox of Subjectivity: The Mind Amidst the Material
The redaction of the autonomous ego that transpired in the 18th century after Descartes, situated the subject in the material composition of the body, leaving the generation of the subject to be explained on purely material grounds.  Increasingly complex behavior, the product of evolutionary advances, (e.g., self-agency/agent causality, consciousness), became through the Cartesian/materialist scheme the product of material forces alone. Yet, for this explanation to suffice material reality must be pre-endowed with properties that have a latent disposition to yield subjective order, a point made by Thomas Nagel in Mind and Cosmos (Nagel, 2012). The posthumanist challenge, however, presupposes that the materially altered - and emancipated and autonomous – subject/ego will remain unchanged.

3. Conciliating Cartesian Metaphysics and Neuroethics through Neuroscience
Modern neuroscience, once the province of single cell analyses only, today tackles empirical questions dealing with mega features of brain operation, like large scale network architecture or faculties such as memory. These current studies, that adopt a methodological legacy from Cartesian conceptions of reality, illuminate the organization and manner of working of the human brain, arguably the most complex natural structure in the known universe. However, they do not explain the why question for the brain and body’s organization, which reflects a supra(meta)physical order, one extrinsic to the brain and necessarily adopted in its design; e.g., the need for unity in individuated and coordinated action. This metaphysical ordering is made evident in neuroscience discoveries and can help to resolve paradoxes introduced by Cartesian thinking and conciliate, in turn, their resolution with neuroethics.

A. Functionalist interpretations of human faculties.
The inability of mechanistic i.e., having a central causal nexus - views of brain operation to explicate higher order argue for a systemic organization in which the brain (and body) are intrinsically and holistically configured, much like the autopoietic, recursive model of Varela and Maturana (1979).   

B. Extended notions of mind
The premise that the mind derives from an elastic and intersystemic organization is challenged by the individuation that is ubiquitous in goal directed, organismal life. The general observation of integrated autonomous wholes that are endemic in natural life reveals, rather, that living organisms must exist as entities in order to express properties like agency (Hooker 2008). Modern neuroscientific evidence is consistent with a dynamical self-organization that arises from within and extends throughout the whole individual, but not beyond him (Allen and Friston, 2016). 

C. Autonomous Ego
The Cartesian notion that the I/ego is segregated from the material form of its expression, is challenged by the failure to account for the appearance of subjectivity in material nature, suggesting, rather, that the material character of the natural world is itself impressed with a latent metaphysical order. The apparent existence of this impressed order seems to mean that subjectivity is not itself a feature derived from the physical reality of the world but rather one imposed from without (Nagel, 20). 

Observations
  • Cartesian attempts to explain causality in nature introduce modern riddles of brain operation affecting neuroethics.
  • Philosophy of science observations on neuroscience may help to resolve these ambiguities and offer a sounder metaethical foundation for neuroethics

References
Bechtel W (2017) Explicating top-down causation using networks and dynamics. Oxford: Oxford University Press.
Bostrom N (2005) In defense of posthuman dignity. Bioethics 19(3):202-214.
Esfeld M (2004) Quantum entanglement and a metaphysics of relations. Studies History Philosophy Modern Physics 35:601-617.
Freddosso AJ (2010) Thomas Aquinas: Treatise on Human Nature. South Bend, Indiana: St Augustine Press.
Hooker C (2008) Interaction and bio-cognitive order. Synthese 166:513-546.
Levy N (2011) Neuroethics and the extended mind. In (J Illes and B Sahakian Eds) The Oxford Handbook of Neuroethics. Oxford: Oxford University Press.
Marion JL (2007) On the ego and on God New York: Fordham University Press.
Maturana HR and Varela F (1979) De Maquinas y Seres Vivos Autopoiesis: La Organizacion de lo vivo. In Boston Studies in the Philosophy of Science. Dordrech: Reidel Publishing.
Moreno A and Mossio M (2015) Biological Autonomy: A Philosophical and Theoretical Enquiry. Berlin: Springer Press.
Nagel T (2012) Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False. Oxford: Oxford University Press.
Onishi B (2011) Information, bodies, and Heidegger: tracing visions of the posthuman. Sophia 50:101-112.

Reiner P (2011) The rise of neuroessentialism.  In (J Illes and B Sahakian Eds) The Oxford Handbook of Neuroethics. Oxford: Oxford University Press.

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