Diagnosed with Hodgkin’s lymphoma in 2005, István Aranyosi commenced a treatment regimen that included chemotherapy in the form of vincristine, a neurotoxic vinca alkaloid that, in his case, resulted in temporary peripheral neuropathy, a condition that caused him “to think about philosophical approaches to consciousness, sensory experience, and the self” (p. 4). The picture of the mind that emerged for him from this period was neither that of “the Cartesian . . . soul in the body as a pilot in the cabin . . . [nor] the contemporary neuroscientific picture of the mind as a brain possessing a body-image, [but instead that] of the mind as distributed in, or infusing, the body, thanks to the [peripheral nervous system (PNS)]” (p. 7). By taking the PNS seriously, István Aranyosi offers an approach not only that convincingly addresses conundrums in the philosophy of mind, but with important ramifications for various issues in neuroethics as well.

Regarding his theory as “part of the . . . burgeoning ‘embodied mind’ school or trend in contemporary philosophy of mind and cognitive science” (pp. x-xi), István Aranyosi refers to it as the peripheral mind hypothesis (PMH). With a focus on sensory systems (versus, for example, dream experience, imagination, memory, and reasoning), the PMH asserts that “conscious mental states typically involved in sensory processes are partly constituted by subprocesses occurring at the level of the PNS” (p. 22, emphasis added). Acknowledging that others within the “tradition” of which the PMH is prima facie a part all take into account the essential role of efferent pathways in conscious experience, István Aranyosi distinguishes his position from theirs by emphasizing the afferent component: “The sensory parts of the PNS . . . [are] constitutive of rather than causing experience” (p. 21, emphasis added).

To illustrate the difference between the PMH and similar theories that take the PNS less seriously, István Aranyosi traces developments in visual awareness research (pp. 25-31), contrasting the “serialist approach, based on Marr’s legacy [in Vision (1982)], according to which the final conscious percept is to be found at the top of . . . [a cortical] hierarchy” (p. 28, emphasis added), with interactionist approaches “that are unlike the serialist approaches in that their model of how conscious experience is generated is an integrated system of mutual interactions, both feedforward and feedback, which at the same time transcends cortical hierarchies” (p. 30, emphasis added). Noting that the serialist approach assumes complex systems whose function is to generate multiple products analogous to an oil refinery’s production of asphalt, gasoline, kerosene, and the like from raw materials, István Aranyosi refers to it as “the refinery view,” whereas he denominates the interactionist approach to which he is sympathetic as “the Christmas lights view,” noting that “it would be crazy to build a lighting system for your Christmas tree such that the electrical impulse travels through a lot of units that manipulate it only to make a single light bulb or LED light up at the very top of it, while the rest of tree is in total darkness” (pp. 30-1).

Similarly, in chapter 3, István Aranyosi reviews theoretical accounts for the neurological mechanisms of pain, noting the failure of central state materialism’s identity statement, “pain = C fibers firing,” to account adequately for the empirical details described by the gate control theory of pain that “superseded its two earlier rivals: the Specificity Theory . . . and the Pattern Theory” (p. 41). Because of the nature of this identity statement and its failure to account for certain empirical facts, István Aranyosi identifies it as an instance of bad/old folk neuroscience, adding that a good alternative should adequately account for such facts, as the PMH does by taking the PNS seriously: The “old folk theory . . . assumes that . . . the pain state is a CNS state, by which . . . [proponents of central state materialism] mean a brain state, typically caused by noxious stimuli and the nerve impulse traveling through the PNS . . . and causing some type of avoidance behavior, part of the notion of behavior being the activity of the efferent nerve firings . . . , whereas the new folk theory . . . [recognizes] that pain is a complex feedforward and feedback process of the relevant integrated CNS and PNS synaptic routes” (p. 45).

But if attentiveness to the empirical details related to the neurological mechanisms of vision and pain reveal the inadequacy of intuitively appealing corticocentric explanations of these mechanisms, then what, if anything, recommends the PMH over other less corticocentric explanations, including the newest, somewhat heterogeneous group of proposals in the philosophy of mind and cognitive science commonly referred to as embodied and embedded cognition (EEC)? To address this question, István Aranyosi commences an exploration of EEC in chapter 4, where he identifies Hilary Putnam’s “brain-in-a-vat [BIV] thought experiment (1982) . . . [as] one of the most discussed . . . in current philosophy” (p. 59)—and then proceeds to elucidate a shortcoming of proponents of the extended mind hypothesis (a particular approach within EEC), who, by equating “the underlying computational/informational patterns going on in the computer . . . [attached to the BIV] with ‘the world’,” (p. 61) have attempted to address what they took to be a case of bad folk neuroscience in the BIV thought experiment: “The BIV has so far been presented in the literature . . . as a passive receiver of stimulation from the computer, when, in fact, they should be thought of as interacting” (p. 63). Without such interaction, “the BIV and its connected computer are like two mirrors facing each other; there is no genuine information in the compound system” (p. 64). For that, “you need a world, in the sense of an extra-neural reality. The computer does not bring about such a reality; computer and BIV are caught in an infinite recursive reflection of meaningless electric signals” (p. 64). In other words, as a representative of a particular approach within EEC (viz., the extended mind hypothesis), the BIV thought experiment fails to account for all that it should and that the PMH, by taking the PNS seriously, can—a conclusion supported by further consideration of the EEC, including not only the extended mind hypothesis, but also enactivism, in chapters 6-8.

Before giving EEC due consideration by the end of chapter 8, István Aranyosi turns in chapter 5 to the Twin Earth thought experiment that Putnam first presented in “Meaning and Reference” (1973) and that is often used to argue for semantic externalism. Given his anti-corticocentric bias, it is rather unsurprising that István Aranyosi expresses sympathy for Putnam’s anti-narrowness—“that is, the claim that meaning is not determined by narrow psychological states, understood as subjective appearances, independent of world-involving veridicality” (p. 78). But, that does not necessarily mean that he is pro-wideness in the Putnamian sense: “The way to reject the view that narrow psychological states determine meaning is not by going to the other extreme, the one subscribed to by Putnam and the externalists, namely that some mental states are wide and, hence, that some parts of the mind are really outside of the individual’s organism. The right way to reject narrowness is to posit the environment-organism causal link as essential to and determiner of meaning. The view preserves Putnam’s realism, which he takes as essential in differentiating his externalism from internalist approaches, but avoids the . . . counterintuitive consequences of externalism” (p. 93). Not surprisingly, István Aranyosi identifies the PMH, which situates the mind-behavior boundary at the fringes of the PNS in the neuromuscular junction, as the locus of this “middle way.”

If István Aranyosi’s development of the PMH is the most novel aspect of The Peripheral Mind, its implications for various neuroethical issues, which he takes up in chapter 9, are arguably the most interesting, particularly for a wide range of counselors and other health care practitioners. His astute analysis of the ethical acceptability of the types of surgeries requested by individuals diagnosed with body integrity identity disorder aside, one cannot help but take notice of his PMH-driven analysis of abortion. Ushered in by the Age of Reason, “self-consciousness” has emerged to challenge conception as the threshold beyond which abortion is morally unacceptable. The trouble with an appeal to the absence of self-consciousness as a justification for a liberal position on abortion is that, when applied consistently, it can also be used to justify morally unacceptable courses of action like infanticide. To get around this disturbing unintended consequence without necessarily returning to dogmatic solutions, István Aranyosi employs a so-called “potentiality argument.” Recognizing the susceptibility of such arguments to defenders of the liberal position on abortion, he distinguishes thin/“mere” potentiality, which “should not be taken as conferring moral properties on the entity who possesses this potentiality” (p. 184), from thick potentiality, which does confer such properties. To illustrate the difference, he offers a culinary analogy in the form of a muffin recipe and three cases relative to that recipe:

A.    Your child . . . [spills] the milk.

B.    You manage to make the mix of egg, milk, oil, and almond extract, but your child throws it in the garbage.

C.    You manage to pour the final mixture into . . . muffin cups in a baking tray and then leave the tray in the preheated oven, but after a couple of minutes of baking, your child takes the tray from the oven and throws it out of the window.

Applying the informal heuristic that adding more of the same kind of stuff to/increasing the magnitude of the developing relatum is all that is required to transform it into its “end product,” we see thick potentiality in the third case alone. In the case of a fetus, István Aranyosi argues, if we take the PNS seriously, we can make a case for sentience, the hallmark of personhood, appearing well before cortical integration. Specifically, “the birth of persons in the case of humans, whose early sensing has the thick potential for self-consciousness, is the moment when the first PNS-mediated signal reaches the brain” (p. 194). István Aranyosi locates this at eight weeks after conception. Hence, an application of the PMH makes it morally unacceptable to abort a fetus after that time.

With errors on no fewer than 25 pages that should have been addressed by the publisher, The Peripheral Mind is not without its distractions, including, for example, misnumbered sub-heads (p. 31), inconsistent numbering conventions within and between lists (the list on p. 128 relies on letters and Arabic numerals, whereas same-“level” lists on pp. 84 and 143, for example, use neither letters nor Arabic numerals, but Roman numerals), and inaccurate internal references (the opening sentence of chapter 8 references chapter 7 instead of the correct chapter 6). Fortunately, these trees fail to obscure the reader’s view of a forest that promises to be of central importance in the philosophy of mind and cognitive science, if not neuroethics as well.

© 2014 Byron D. Smith

Byron D. Smith’s formal education encompasses undergraduate studies in psychology and philosophy, including supervised research on mental self-control with human subjects under Daniel M. Wegner, the former John Lindsley Professor of Psychology at Harvard University. He holds a graduate degree in religion from Yale University, where he explored the free will/determinism problem within the context of an early theological debate between St. Augustine and Pelagius. In addition to his work as a German-to-English translator, he has served in various editorial capacities, including for the world’s largest educational publisher and a leading public relations firm in the San Francisco Bay Area.