1. Introduction

Until recently the topic of disability has been either largely overlooked or neglected throughout the philosophical history of the west. If and when western canonical philosophers reference physical or intellectual disability, such reference is often used to contrast between a normative conception of human embodiment (i.e. rational and able-bodied) and those contingencies that mark a failure to achieve this ideal (e.g. contingencies, impairments, etc.) (Byrne 2000). In effect, individuals with disabilities have been categorically defined against the traditional philosophical subject, an agent whose embodiment entails certain rational or cognitive capacities associated with what is normal, healthy, or human. This essay argues that the tendency to exclude individuals with disabilities from philosophical discourse is rooted in the attempt to apply rationally-derived principles to human embodiment. To establish this thesis, this essay focuses on Plato's Republic as one of the first, foundational philosophical texts to specifically argue that an ideal city governed by reasonableness should actively kill individuals with intellectual and physical disabilities because such individuals embody injustice as the lack of order. Although the programs of euthanasia found within the Republic have been largely analyzed simply as historical facts about ancient Greek culture, Plato should be understood as one of the first philosophers to introduce a conception of normative human embodiment based on rationally-identifiable criteria in direct contradistinction to a defective form of embodiment (see Moravcsik 1976; Galton 1998; Carrick 2001; MacFarlane and Ronald 2004). That is, Plato's argumentation in effect creates a philosophical conception of disability as a type of deficiency when compared to that which is considered fully rational, healthy, or ideally human. Despite the relative dearth of scholarship on this particular issue, there are some notable exceptions that focus on Plato's considerations of disability without adequately addressing the philosophical and rational sources of such argumentation (Jowett 1986; Goodey 1992; Stainton 2001; Becker 2005).

This essay concludes that because philosophical discourse is predicated upon rationality and the application of rational principles, the exclusion of individuals with disabilities due to considerations of normative conceptions of embodiment will always remain an inherent possibility within human reasoning. The application of rational principles entails that incongruous, wasteful, and otherwise defective elements must be removed, and if such principles are instrumentally applied to human embodiment, then the result is that certain human beings themselves embody that which is inimical to reason and must be purged. However, as normative considerations of rationality and human embodiment will remain an inherent possibility, such attempts will also necessarily fail to adequately address human embodiment insofar as such rationalized schemas exclude some individuals and deny inevitable borderline cases to appear rationally coherent. The attempt to use rational principles to derive an intelligible basis for human embodiment exists only by denying those individuals that lie outside of and beyond reason, strictly construed. Thus rationalized conceptions of normative human embodiment cannot be fully deduced from philosophical principles alone without incompleteness, and only empirical rather than a priori rational considerations can adequately address the individuality and contingency of concrete human embodiment.

While the exclusion of individuals with disabilities based upon philosophical or rational grounds in particular is beginning to currently decrease, understanding the motivation behind the philosophical attempt categorize a normative conception of embodiment is important as such exclusion will remain a possibility in the future. Additionally, numerous contemporary philosophers still appeal to a normative conception of embodiment when considering whether or not a being is a "person" who ought to enjoy certain medical and ethical considerations owing to cognitive criteria or considerations of physical ability. This contemporary trend is most explicit in the work of some bioethicists and utilitarian thinkers who attempt to categorize rationally-identifiable criteria for accepting or rejecting individuals based upon considerations of normative embodiment and the failure to achieve this embodiment as represented by disability; I refer mainly to thinkers such as Michael Tooley (1983), Peter Singer (1993), Helga Kuhse (1987), James Rachels (1986), and most recently, Alberto Giubilini and Fracesca Minerva (2012).

2. Background

This subsection provides some necessary background information on the study of Platonic thought as well as the historical and contemporary usage of terms such as 'impairment' and 'disability.' In contemporary usage and despite disagreement, 'impairment' is used as a descriptive term for the improper function of a physical ability or mental faculty, whereas 'disability' is used to characterize the interaction between individuals with impairments and the social structures that exacerbate or minimize these impairments (Lindzey 1989). Today the sheer number of individuals with disabilities in the world is perhaps enough to require a philosophical account of the concepts surrounding disability. It must be noted that one reason behind the historical, philosophical, and conceptual neglect of the topic of disability is the economic and technological limitations placed on the survival of such individuals (Becker, 2005, 10). However, it must also be recognized that individuals with disabilities have been socially and philosophically marginalized because such individuals may fail to live up to strict philosophical standards associated with human nature as a rational and able-bodied nature (Byrne 2000; Ho 2007). While an attempt to address this historical neglect can now be found in many scholarly areas including feminist theory, bioethics, critical disability theory, and social or political philosophy, such interest does not necessarily address the philosophical source of such neglect rooted, as I will argue, in a particular application of rationality to embodiment (Sen 1992; Kittay 1998; MacIntyre 1999).

While it is tempting to believe that the ancient Greeks had a similar conception of disability based on contemporary terminology and by way of the ancient Greek word adunatos (incapable), the conception of disability both socially and philosophically has not remained static throughout time periods and across various cultures. As Martha Rose (2003) in The Staff of Oedipus reminds us, the substitution of adunatos for 'disability' would not be accurate because disabled individuals in ancient Greece were not a clearly defined subcategory of human beings (p. 98). That is, the conceptual distinction between categorically unimpaired individuals on the one hand and impaired individuals on the other was not a common aspect of ancient Greek culture. Instead and owing to the hazards and particularities of ancient Greek life, there existed a spectrum of human embodiment ranging from minor to severe impairment resulting from birth or accident later in life.

Nevertheless, I have chosen to use 'impairment,' 'disability,' and "individuals with disabilities" in this essay to describe the rejected individuals in the Republic for the very reason that Plato's defense of euthanasia entails the introduction of a categorically distinct subset of human beings predicated upon the application of reason that was not found prior in ancient Greek culture. While I am in agreement with Lennard Davis (2012) and others who trace the history of disability to conceptions of "normalcy," and by correlate "ab-normalcy," as functional products of 19^th century medical and statistical analysis, I believe the conceptual roots of disability must be traced back to philosophical sources in antiquity and the functionality of reason applied to human embodiment as I will make apparent (p. 3-5). The importance of Plato's claims and argumentation concerning individuals with disabilities is that this argumentation amounts to a justification based upon a philosophical logos or reasoned argument rather than through an appeal to a mythos or some other socially constructed cultural artifact. However, given my usage of such terminology, I would not want to deny that the difficulty with terms like 'impairment' and 'disability' is that these terms cover an extremely large and diverse group of human beings with little actual commonality. Then again, it is this very conceptual limitation that I am focusing on by inspecting how concepts are formed and upon what rational justificatory basis they rest in the philosophical tradition of the west. Indeed, despite the actual diversity among individuals with disabilities, there is a tendency to categorically group individuals with disabilities together under one conceptual heading, a conceptual move that creates a negative category of disability through the characterization of the "correct" human embodiment that proceeds logically from a particular application of reason upon human embodiment.

Turning briefly to the study of Plato, the Republic is widely considered to be a middle Platonic dialogue and believed by many to be one of the most explicit articulations of the specifics of Plato's thought. I must note that I believe it is difficult, if not impossible, to determine which aspects of the dialogues are attributable to Plato himself and which are meant to serve a heuristic function. The dialogues present an array of philosophical positions and Socrates himself in the dialogues argues in favor of conflicting philosophical views. Nevertheless, I will state that "Plato argues" or "Plato defends the claim" because whether or not Plato himself agreed with a particular piece of philosophical reasoning, it is now within the philosophical tradition that continued to repeat similar argumentation concerning euthanasia for individuals with disabilities, most explicitly by the other foundational western philosopher Aristotle (cf. Politics VII ch16 1335b20-25). Indeed, Plato sits at the foundation of philosophical discourse of the west, and it is often to his work that contemporary authors still turn when attempting to support argumentation through authority or, for example, tracing the historical justifications of infanticide generally and against neonates with disabilities in particular as Peter Singer and Helga Kuhse undertake in Should the Baby Live? (Kuhse & Singer 1987, 111).

In terms of historical background, given that the Republic was written after Athens's historic defeat at the hands of Sparta in the Peloponnesian war, the resemblance between Spartan programs of infant exposure and euthanasia in the Republic are most likely deliberate. Although Plato had no knowledge of modern genetics, his conceptions of euthanasia and selective breeding were drawn from examples taken from animal breeding in the form of husbandry and the infamous child reading practices of Sparta (cf. Galton 1998, 265). However, the crucial difference between Sparta and the ideal city of the Republic is that Plato argues explicitly against cities like Sparta that are completely structured around the end of war rather than social harmony, justice, or the Good. Indeed, Plato seems to be attempting to correct the errors and shortcomings of Athens and Sparta, especially following the political turmoil of the period of the 30 tyrants. Thus, the resemblance between Sparta and the ideal city is partially superficial and partially a critique insofar as Plato provides distinctly philosophical reasons for the treatment of undesirable infants as a means for the achievement of greater social harmony rather than through an appeal to cultural habits or preparation for war.

3. Souls, Bodies, and Cities

Before turning to the specific argumentation concerning the treatment of individuals with disabilities in the Republic, a brief analysis of Plato's teleological conception of human embodiment must be understood. More specifically, the reasoning put forth behind the proposal of using rationality to manipulate individual human bodies and collectives is fundamentally important for understanding the relationship between philosophy and disability insofar as the rationalization of individuals with disabilities follows from others commitments concerning the nature of the world, health, and the human soul.

The conception of human embodiment put forward in the Republic by Plato, and by correlate the rejection of defective human embodiment in the form of euthanasia, marks an important development in Platonic thought. In the early, so-called "Socratic" dialogues, Plato has Socrates argue in large part for a type of dualistic intellectualism whereby the reasoning faculty (nous) of the human soul (psychē) is prioritized over and above the physical body (Reynolds 2004). That is, the physical body is primarily equated with the transient nature of matter within the realm of becoming (genesis) as distinct from and ultimately contrary to philosophical wisdom because the body through itself has no rational access to the intelligible realm of ideas (Reynolds 2004; cf. Phaedo 73b-74b; Meno 81b-82b). However, and despite this apparently crude prioritization of the soul over the body in the early and early-middle dialogues, Plato presents a much more nuanced understanding of human embodiment in the Republic by introducing a tripartite conception of the soul divided into three interrelated though distinct aspects, the rational (nous), spirited (thumos), and appetitive (epithumia) parts (Republic 437b5-441b in Hamilton & Cairns 1961; Brickhouse and Smith 2002).

In so doing, Plato shifts from characterizing human existence as the prioritization of the intellectual faculty of the soul over and above the physical body to a conception of the soul as constituted by a rational capacity as well as non-rational and bodily aspects previously neglected. The crucial difference between the early-middle conception of the soul and the tripartite conception presented in the Republic is the claim that the natural and proper telos or goal of the rational soul is not to purge the soul of the bodily entirely, but to organize the non-rational aspects of human existence into a harmonious totality (441e4-442d3). More importantly for this essay, the tripartite conception of the soul opens the door for the direct, rational management of human embodiment whereby the physical body and the material world can and must be made to accord with the dictates of reason. The imperative to use reason to manipulate the natural world follows from the belief that reason itself functions as the distinctive feature of human beings who are products of an intelligible natural order that can and must be maintained through the proper application of rational principles (Broadie 2009).

Based upon a teleological and naturalistic conception of human embodiment and influenced by Pythagorean and Empedoclean conceptions of nature (physis), medicine, and health (hygeia), Plato understood bodily and psychical health not merely as medical states of the body but indications of the proper functionality of human nature itself (Carrick 2001, 37). Specifically, maintaining health and the equilibrium of humors is most explicitly tied to the teleological end of human nature in book IV of the Republic wherein Socrates argues that "to produce health is to establish the elements in a body in the natural relation of dominating and being dominated by one another, while to cause disease is to bring it about that one rules or is ruled by the other contrary to nature" (444d3-6). Health is thus characterized not as the contingent condition of a particular individual's body considered in isolation, but as an objective good associated with order, beauty, and proper functionality as a type of harmony (harmonia). Contrastingly, disease and dysfunction are associated directly with disorder, ugliness, the bad condition of the soul, and most importantly for the Republic, injustice as a type of disharmony.

In book II of the Republic, Plato puts these considerations in to practice by using the image of a city built in speech to illustrate the requirements of both individual and collective justice (dikaiosynē) as a type of harmony consummate with the order of the natural world and ideal human embodiment. Initially, Socrates speaks of a city of material necessity characterized by a principle of functional specialization such that each individual has a specific societal role determined by natural predisposition combined with a proper education (370b1-2). Even though Socrates' interlocutors reject the city of material necessity as a city fit for only beasts, the principle of specialization mirrors the tripartite conception of the soul such that each of the three aspects of the soul are aligned with the three social classes of the ideal city of luxury, namely the ruling guardians, the auxiliary guardians, and the producers. Following this schema, a city is ideal and can be considered just insofar as each individual and class is harmonized into a larger totality in the same way that the soul parts each serve one, and only one, respective function (Greco 2009). While this may appear to be a simple repetition of ancient Greek assumptions concerning the proper role of an individual based upon considerations of station, class, or family, it is important to note that the ideal city described in the Republic is not predicated upon slavery, unequal education of similarly proficient men and women, or even a completely fatalistic conception of birth in relation to the three classes (Gadamer 1986). Indeed, it is important to realize that Plato's philosophical considerations of individuals with disabilities in many ways stands in stark contrast to the rather radical departure from Homeric Greek culture found in these departures and perhaps most specifically the dissolution of familial ties for the guardians.

Thus the principle of specialization as a rational principle continues to be important throughout the Republic because it is based upon the belief that what is rational is a function of what is ordered, useful, or measured in relation to a given circumstance or thing. More specifically, Socrates argues that rational principles of organization ought to dictate social policy, and reason can and should be used to manipulate the minds, souls, and bodies of the citizenry to create the type of individual and social harmony identified with justice (519el-520a4; cf. 420b). The end result of these considerations is that because harmony represents the ideal and natural end of individual and collective human nature, to be human in an ideal, normative sense is equated with the physical, rational, and pedagogic ability to actively harmonize that which is otherwise disparate and non-harmonized within human embodiment.

If proper human embodiment is characterized by the physical and rational ability to actively harmonize the soul parts and material body insofar as health is an objective good, then the lack of this ability is an instance wherein the natural and normative telos of human nature has been disrupted or has failed. Correlatively, given this Platonic conception of normative human embodiment created through the application of rational rules or norms, it is already clear that sufficiently intellectually or physically impaired individuals cannot obtain justice and entrance into the ideal city by being shaped both rationally and corporeally toward this end, if they are unable to remove what is bestial or subhuman (i.e. that which is dis-ordered) (Rist 1996, 116-117). The difficulty at the outset is that, for Plato, impairments cannot be understood simply as the otherwise neutral improper functioning of a faculty or capacity, and thus disability cannot be defined by the interaction between individual with impairments and society precisely because society ought not tolerate such individuals in the first place. This consequence follows "logically" from assumptions concerning normative conception of embodiment and rationality such that individuals who lack these capacities are de facto rendered sub-human or animal-like, a defective type of embodiment identified with injustice that must be purged through rational manipulation in the form of active and passive euthanasia (see, Sorabji 1993; Stainton 2001).

4. Philosophical Arguments for Euthanasia and Infanticide in the Republic

Plato does not provide an explicit doctrine of physical and intellectual disability in the Republic, but the arguments presented concerning normative bodily form and intellectual ability lead directly to a rationally formed conception of disability in the bodily rejection of defective variants of human embodiment. The importance of such argumentation is that the very existence of individuals with disabilities becomes an icon or embodiment of disorder, dysfunction, and injustice that must be purged. The rejection of individuals with disabilities in the Republic rests on three primary claims: first, some individuals with disabilities do not have a quality of life associated with human dignity (Republic 406b3-c); second, sufficiently physically impaired individuals cannot fulfill any societal function as dictated by the principle of specialization (406d-e); third, intellectually impaired individuals cannot respond to moral education because they are ethically "incurable" (aniatous) and "of defective birth" (kakophneis) (410a1-3).

The rejection of individuals with impairments as a type of disability arises in book III of the Republic within the context of ideal medical and ethical practices. While it may appear that these arguments only apply to the already scrutinizing eugenic programs applied to the guardian class, Socrates reiterates that these medical practices ought to be established by law and applied to any ideal city as a whole as a rational medico-ethical dictum (409e3). As noted earlier, Plato could have intended these considerations to be only basic guidelines that mimic the Spartan system, but the categorical and distinctly philosophical justification put forward makes this interpretation less plausible. Indeed, Plato does not put forth an empirical framework in which principles concerning human embodiment can be tested, amended, and implemented. Instead, he attempts to provide absolute principles concerning correct bodily form and mental capacity to establish a social situation wherein individuals with certain impairments have been rationally defined out of existence.

Argumentation in favor of a general form of euthanasia in the ideal city is predicated upon the idea that some types of human life are not worth living. While such a principle appears plausible if one imagines a life circumscribed by horrible pain or emotional suffering, as presented in the Republic, this principle follows from considerations of the rational functionality of the individual in question (406b3-c). That is, if rationality is understood as the distinctive and most divine function of the human soul, then individuals who lack such functions are relegated to the realm of otherwise "lower" animals that lack a dignified life or right to life. This type of quality of life consideration is explicitly not in the "interests" of the individual in question, especially given that the individual in question may not even have interests at all owing to a defective rational aspect of the soul.

The rejection of individuals with physical impairments as a program of an ideal city rests on the principle of specialization. As noted, initially the ideal city is characterized by material necessity insofar as each individual receives and provides only as much as is needed, and consequently there is no luxury or scarcity. This original, "true," and "healthy" city can exist because each individual performs one and only one specialized function (372e5-6). Thus, individuals who are unable to perform their specialized function due to birth or accident both decrease productivity as well as embody a type of natural resistance to the internal logical consistency of an ideal city by representing a potential threat that must be allowed to die off "naturally" or without recourse to extraordinary medical measures. I have reconstructed the argument here to illustrate exactly how such a conclusion follows "reasonably" from certain background assumptions:

1. The origin of a city is the inability of an individual alone to provide all required basic goods (food, housing, etc) (principle of the origin of a city; 369b5-7).
2. The fulfillment of basic goods ideally requires a principle of specialized labor such that each individual has only one particular societal task designated by natural inclination and educational upbringing (correlate of premise 1; principle of specialization; 370b1-2).
3. An individual's function in a city is to fulfill a specialized productive role and it is on account of this role that the individual gains access to societal goods such as medical treatment (implication of premise 1 and 2; 369e-370c5)
4. If an individual cannot physically fulfill his (or her) specialized societal task, then he (or she) cannot produce goods or services that fulfill any function for a city and thereby earn the use of basic goods through contribution and production (negation of premise 3; 406c-d; 408a-b).
5. Incurably physically injured or impaired individuals cannot fulfill their associated societal task (assumption; 406d6-7).
6. Therefore, incurably physically injured or impaired individuals do not deserve medical treatment (a societal good) and should be allowed to die in a process of passive euthanasia or exposure (406d-e).

While this argument appears to be one of economic considerations based upon the inability of some individuals to access societal goods, there is a related consequence that a failure to fulfill a societal task is also an unbefitting failure of human embodiment characterized through supposed quality of life considerations. Socrates attributes this medical principle of least activity or passive euthanasia to be in accordance with the god of medicine Asclepius by framing the discussion in terms of what we might refer to as "common sense," despite the philosophical presuppositions that underlie this entire line of argumentation (406d1). The treatment of individuals with physical impairments from birth presents an instance wherein medicine, even in the form of indirect care (e.g. canes, artificial limbs, etc), should not be given because such impairment is not temporary, cannot be cured, and impedes an individual from fulfilling a societal function. However, it is important to note that there is nothing within the formal argument that specifically selects for individuals with physical impairments present from birth such that theoretically any individual may be refused medical treatment if and when physical impairment occurs later in life.

Plato proposes that the ideal city should practice active euthanasia in the form of infanticide for those neonates who are defective or ethically "incurable" (409e-410a) (cf. Brickhouse and Smith 2002, 33). Plato's justification for the active killing of these individuals rests not on only their lack of contribution to society, but on the proposition that some individuals lack the intellectual capacity to respond to moral education from birth. Following from considerations of medical ethics, Socrates asserts that an ideal doctor should be acquainted with illnesses, but if he or she is consumed by disease then any consequent diagnosis will be corrupted as well (408d-e). Similarly, moral goodness requires the ability to judge good and evil in others without being consumed by evil itself. That is, the ability to adjudicate between good and evil is gained through good role models and a proper moral education. However, cultivation of a sense of good and evil necessarily requires an antecedent intellectual or mental capacity responsive to moral education for subsequent cultivation to be affective at all. Given these requirements, some individuals do not have the capacity to be educated in ethical matters by nature, and therefore some individuals simply cannot obtain moral goodness on account of a defect in the rational aspect of the soul (410a). I have reconstructed the argument and it proceeds as follows:

1. Moral goodness requires the ability to adjudicate between good and evil (this includes the ability to intellectually apprehend and refrain from committing evil; 409b3-c).
2. The ability to adjudicate between good and evil rests on correct moral upbringing and education (409c-e).
3. Individuals who are unable to judge between and thereby choose good actions over evil actions can only bring about evil (implication of the negation of premise 1; 409d-e)
4. Individuals who can only bring about evil should be put to death for the greater moral good of society (contrary to justice as individual and collective harmony; 410a4-5).
5. Certain individuals from birth lack the capacity to respond to moral education and by implication the mental capacity required for the apprehension of good and evil (assumption; 410a1-3).
6. Therefore, individuals who are "of defective birth" and "incurable" should be put to death (410a1-3).

Despite the explicitness of this argument in favor of infanticide, the specifics of such argumentation remain unclear. Specifically, it is not clear who within the ideal city would be tasked to carry out such infanticide and upon what empirical criteria such judgments could possibly be made. Whereas infant exposure in Sparta resulted from an unsatisfactory inspection by the ruling elders, Socrates implies that this task would fall on the midwife at the neonatal stage of life as an initial checkpoint prior to full acceptance into the moral and social community of the city. Nevertheless, it is uncertain how the midwife or inspector could evaluate an individual's intellectual, let alone moral, capacity at such an early stage or through a snapshot at infancy. The most plausibly I can present this argument is that Plato is arguing that certain perceptible features of an impairment indicate the lack of mental capacity, but these perceptible features are not the direct cause of the reduced capacity itself. For example, the perceptible features of Down's syndrome are not the direct cause of intellectual impairment, which is typically also present. Thus it is at least possible that midwives, or individuals who have had exposure to numerous infants, could determine what is the average or "normal" level of neonatal development relative to mental capacity.

However, the concern behind this particular argument is only superficially with the "threat" posed by citizens who are somehow compelled to do evil or injustice by birth for numerous individuals with fully formed intellectual capacities can and do commit unjust acts, perhaps precisely because of such cognitive abilities. The importance again rests on the way in which individuals with intellectual impairments become an icon for the failures of nature and objective limitation of any potential ideal city. Indeed and according to the medico-ethical programs of the ideal city, Plato's reasoning necessitates that individuals with certain impairments should be rejected unconditionally and rooted out actively because such impairment is rendered the determinate factor in an individual's social, economic, ethical, and even metaphysical status as a human being, considerations determined upon the basis of an application of rational principles to human embodiment.

5. Reason and Normative Embodiment

The preceding sections detailed the background assumptions and reasoning used to philosophically justify the active and passive euthanasia of individuals with disabilities in the Republic. In this final subsection, I focus on the contemporary import of the relationship between human reasoning and a normative conception of embodiment. It is tempting but simplistic to merely reject these arguments and actions against individuals with disabilities as an outdated or backward way at looking at the world. While it is clearly the case that the social, economic, and ethical situation of the contemporary world differs vastly from Plato's own, if such argumentation is rooted in the application of rational principles to human embodiment, then the particular historical circumstances may vary while the potential exclusion of individuals with disabilities will remain an inherent possibility of reason. Moreover, it must also be noted that an appeal to a normative conception of embodiment has excluded and continues to exclude other "types" of human beings along the lines of gender, race, and class, throughout the world. Contemporary western societies do not currently enact programs of euthanasia similar to the Republic, due in part to Judeo-Christian-Islamic prohibition against certain types of infanticide. However, the current acceptance of many individuals with disabilities is by no means automatic or guaranteed despite the implementation of various medical ethical boards and safeguards, especially given the apparent "natural" aversion to deformities and indicators of disease sometimes associated with sin or personal moral failure.

The contemporary importance of Plato's argumentation in the Republic is that it follows from and is rooted in the application of rational principles on human embodiment. Plato believed that the natural world was constituted by an intelligible order that could be understood by human rationality insofar as reason itself is product of this order. While most contemporary philosophers do not necessarily believe that the natural world is teleologically ordered, the importance lies in the tendency of human rationality to favor order, intelligibility, and the abstract principles that underlie particular things. Indeed, even without an explicit teleological conception of nature, it is because reason seeks to purge elements that are contrary to reason (e.g. contradictions, inefficiencies, ambiguities) that considerations of normative embodiment and non-normative or defective embodiment will continue arise as rational byproducts. As health continues to be considered an objective, rational good for human beings, what is considered unhealthy or defective as embodied in particular individuals leads a philosophically-based rational exclusion of such elements deemed inimical to reason itself. This is not to imply that this process is inherently conscious or even voluntary, especially given that the objective conditions and limitation of human existence are clearly not optional. Instead, human reasoning is circumscribed, I believe, by an evolutionary process that has led to the cognitive faculties we now possess. Indeed, it is no wonder that abstract considerations of what is desirable or good for human beings as such result from the generation of generalized principles concerning human embodiment if such considerations are conducive to human survival.

Although considerations of normative embodiment are rooted in human reasoning, the inherent difficulty with such considerations is that abstract rational principles or criteria fail to give an adequate account of human embodiment. The desire to characterize what is the ideal or normative embodiment for human beings amounts to a denial that human embodiment itself is constituted by contingency, error, and defect - just as all things within the realm of becoming (genesis). It is only by concealing this metaphysical fact about the world that normative conceptions of human embodiment can appear to be complete and even "rational." Reason seeks the intelligibility of the natural world and it is only when this intelligibility is thrown into doubt by the existence of elements that lie outside of this rational order that actions like euthanasia must be enacted and given a philosophical justification. That is, as was clear in the Republic, the very existence of individuals with disabilities stands as an affront to reason and reasonableness precisely because this type of human embodiment should not occur if the natural order is truly intelligible or can be made to be intelligible. Rational principles are abstract, general, and if rooted in logical or natural necessities, must admit of no exceptions. Human embodiment, however, is concrete, individual, and conditioned by particular exceptions and contingencies. Human embodiment is simply not the type of thing that can be carved at the joints by reason alone given the very nature of what it means to be embodied and human.

The result of the failure inherent within the application of rational principles to human embodiment is the reduction of certain human beings into rationally-identifiable and ultimately arbitrary criteria. Considerations of normative human embodiment appear to characterize what is best, ideal, or normal for human beings only by denying or otherwise concealing the failures of natural developmental processes. Human reason attempts to find the world intelligible, and when this intelligibility is not found, it must be created. However, the application of rational principles upon human embodiment no longer even addresses concrete human beings. Instead, these individuals are reduced to particular rationally-identifiable attributes, faculties, or potentialities that appear valid. Nevertheless, these rationalized schemas will always be arbitrary because of the nature of human embodiment, for it is far from clear that any non-arbitrary criteria, for example, concerning how many neurons or IQ points are required to be considered "human" could ever be put forth without controversy.

This is not to say that we cannot have any conception of what is average, healthy, or statistically "normal." But it must be noted that empirical methods of inquiry are much better suited for the analysis for human embodiment as there will always be borderline cases and exceptions to any rationalized criteria concerning human embodiment, given that the contingency of human embodiment seeps into these schemas despite attempts at philosophical purification. In one sense, the "humanity" of these excluded individuals is already reduced or removed as soon as abstract or generalized principles are used to mediate the actual particularities of their existence. Indeed, reason does not and cannot simply "find" the world as intelligible for the very reason that the world generally and human embodiment in particular lacks the type of intelligibility that arises through the products of abstract human reasoning. Thus, individuals who fail to live up to the standards of normative conceptions of human embodiment are excluded philosophically precisely because they stand in opposition to the human attempt to understand the world and human embodiment as a products of the world, an attempt that amounts to the traditional western philosophical goal.