Corps de l’article

Consider Three Individuals

Vicky is an adult woman with profound cognitive disabilities. She has a mental age of 5 months, is doubly incontinent and bottle-fed. Vicky spends each day in a wheelchair, incapable of all but minimal responses to her caregivers. She will never have a sense of past and future or of herself as a person. Vicky has no language, inner life or purposive agency; she cannot engage in any important elements that characterize human lives – meaningful communication, significant relationships and productive activity (1).

My adult son David is intellectually disabled from a prenatal brain injury causing periventricular leukomalacia (PVL). PVL involves the destruction of small areas of brain tissue around fluid-filled areas called ventricles – the damage creates holes in the brain’s white matter. His evaluative scores fall within the moderate range of mental impairment: he does not read or write, is nonverbal and has significant deficits in adaptive living skills. He will need residential arrangements, employment assistance and other disability services his entire life. David is, however, more than PVL. He has numerous virtues (cheerfulness, humor and empathy), talents (he rides his recumbent tricycle hundreds of miles each summer, stocks shelves at a food pantry and plays Special Olympics sports) and relationships (with family and friends).

My daughter Sarah is an intellectually typical adult. She completed graduate school in Europe and lives in England, where she is program manager at a disability agency. She and her husband travel extensively, brew beer, ride motorcycles, run marathons, attend concerts and entertain a wide circle of friends.

The common belief is that disability is bad for and harmful to the person who is disabled, that it has a negative effect on well-being. Some disability rights activists and philosophers, however, assert that disability has little or no impact on how well a person’s life goes, that it is neutral with respect to flourishing. In recent articles Stephen Campbell and Joseph Stramondo (2,3), while rejecting both views, claim that we cannot make any broad generalizations about the effect of disability on well-being. Whether they are right about physical and sensory disabilities, I do not know; but I shall argue that they are wrong about intellectual disabilities (ID). A broad generalization about ID is justified: it always has a negative impact on quality of life, even though there is no single negative impact.

What Campbell and Stramondo Think

Campbell and Stramondo group all disabilities together – physical, sensory and intellectual – and since their analysis covers disabilities in general, I interpret their claims as applying to ID in particular. They reject the Standard View that ID has a negative impact on well-being in the vast majority of cases. They also reject the Neutral View that in most cases ID has no impact on well-being. They affirm, instead, the Complicated View that ID has an individualized impact on well-being which makes it difficult to generalize about whether it is bad or not. This is true on both subjective and objective accounts of well-being (3).

Why the Standard View is False

There are four ways in which ID might be bad for a person, and the Standard View is false on all interpretations.

  1. ID is not intrinsically bad. By itself, apart from its consequences, ID does not make a person worse off. While being pain-free is a basic element of well-being, possessing typical intellectual abilities is not. In isolation from its effects, ID on its own is neither good nor bad, but neutral (3, pp. 156–157).

  2. ID is seldom instrumentally bad. It is true that ID can prevent a person from obtaining particular goods of life, experiencing certain things and performing specific tasks. But the fact that ID is instrumentally bad in some ways does not mean it is instrumentally bad in all ways. This is because particular goods like social relationships can be achieved in multiple ways; while ID cuts off some avenues for realizing human goods, it does not destroy all avenues to them. Even if ID does block specific goods entirely, the person still enjoys enough functionings to have a good life overall. Social arrangements and individual characteristics (what a person is like and how they respond to their condition) can also prevent the achievement of important goods and negatively impact well-being. Circumstantial variations in life lead to diverse variations in well-being and so it is impossible to make any simple generalizations about the disadvantages of ID itself (3, pp. 157–160).

  3. ID is not comparatively bad. It does not make a person’s life worse than it would have been without ID. A judgment of relative badness requires a comparison between someone’s actual well-being with ID and their supposed well-being without ID. This comparison, however, cannot be drawn: “counterfactual opacity” makes it impossible to know that a person would have had a better life without ID than they have with it – any such judgment reflects “ableist fantasy.” In addition, ID is identity-constitutive – it is central to who the individual is and shapes their identity in substantive rather than incidental ways. Being unavoidable, its removal would obliterate the person (3, pp. 160–161).

  4. ID is seldom overridingly bad. Few conditions are so “very, very...bad” – so awful – that life with them is guaranteed to be bad all things considered and on the whole. Most IDs are compatible with important goods of life such as knowledge, achievement, happiness and relationships. ID may be a local bad that reduces well-being in some aspects of life, but to label it as a global bad that makes life go worse in all dimensions is reductive synecdoche – a general, negative assumption about a whole human person on the basis of one characteristic (3, pp. 161–162).

These considerations lay to rest the Standard View, the generalization that ID tends to be bad for a person most of the time.

Why the Neutral View is False

That the Standard View is false does not mean the Neutral View is true, that ID is neither good nor bad for a person. Campbell and Stramondo affirm that ID is intrinsically neutral and deny that it is overridingly neutral. But it is misleading to think that ID has no instrumental or comparative impacts on well-being; in combination with a person’s internal dispositions and external environments, ID tends to have momentous consequences for their lives. Sometimes this influence is for the worse: ID can lead to bad things and prevent good things, but with varying disadvantages due to contingent factors (3).

Why the Complicated View is True

Campbell and Stramondo reason that, since the Standard and Neutral Views are false, the Complicated View must be true. We cannot generalize about the impact of ID on well-being because of three facts.

  1. There are variations between types of ID. Inter-disability variation occurs because ID comes in different types, e.g., Fragile X, Down syndrome, PVL, autism and other diagnoses. Each condition has varying impacts on intellectual functioning.

  2. There are variations within types of ID. Intra-disability variation occurs because ID comes in different degrees, i.e., mild, moderate, severe and profound. Each level has varying effects on mental abilities. Down syndrome, for example, is not expressed to the same extent and in the same way in each case; it has considerable variation and while most people have mild or moderate symptoms, some are severe.

The fact of significant variation between different IDs and within the same ID means that we cannot generalize about the impact of ID on well-being (3, pp. 165–166).

  1. IDs are high-impact traits. Low-impact traits (such as being left-handed) are causally inert; they are mere differences that have little or no effect on quality of life. But high-impact traits (such as ethnicity and sex) have significant causal effects on how someone’s life goes. ID substantially shapes personal well-being; it has varying impact both in combination with social arrangements and individual dispositions as well as apart from these factors (3, pp. 166–168).

Why ID is Probably Comparatively Bad

Campbell and Stramondo concede that it is probable that ID is comparatively bad: if we consider averages rather than the vast majority of cases, then ID is likely to make a person worse off. Two types of ID, in particular, reduce average well-being: severe congenital disabilities like Tay Sachs Disease are comparatively bad because they significantly undermine capacities necessary for flourishing; acquired disabilities like Traumatic Brain Injury are comparatively bad because they involve transition costs. In addition, unfriendly social environments can create lower quality of life. These factors explain why the average person with ID has a worse life than the average person without ID (3, pp. 168–169).[1]

Summarizing the Complicated View

Campbell and Stramondo do not understand human flourishing in terms of species essentialism – a common, core nature by which all persons are measured. Instead, whether a particular individual flourishes is contingent; it depends on the specific circumstances of their life (4). They conclude that:

  1. “the Standard View is false... [It] is simply untrue that, as a general rule, IDs are bad for those who have them.”

  2. “[While] most IDs are intrinsically neutral, we cannot generalize about whether IDs in general are good, bad or neutral for people.”

  3. “It may be possible to generalize about ID’s likelihood of rendering a person worse off to some extent” (3, p. 176).

The countless variations in IDs and life circumstances create very different patterns of well-being and thus no simple generalizations can be made concerning the impact of ID on quality of life. Instead, “the relationship between ID and well-being is a complicated one” (3, p. 176).

What I Think

I agree with Campbell and Stramondo on several things. We should avoid the simplistic assumption that ID leads to poor quality lives. The relationship of ID and well-being is complicated; both internal functions and external circumstances vary, and so assessing the precise effect of ID on quality of life is difficult. In evaluating the impact of ID on well-being we should not ignore the positive testimony of people with ID concerning their quality of life. Intersectionality also matters: people with ID from rich families or who have many loved ones may experience less overall disadvantage than people without ID from poor families or who are lonely (5, p. 30 and 62). There is no single dimension of well-being and disadvantage; a person with ID may flounder with respect to meaningful activity but flourish in their personal relationships. As David Wasserman and colleagues (6, p. 20) note, we should not accept “unjustified or overbroad generalizations about the impact of impairments on well-being, ignoring the highly variable effects of different impairments in different settings.” Vicky’s profound ID has a significantly different effect on flourishing than David’s moderate ID does; social environment and individual temperament also affect quality of life in multiple ways.

But I disagree with Campbell and Stramondo on other things. They come close to the Neutral View that there is nothing essentially worse about having ID than lacking it. Campbell and Stramondo acknowledge that their “response to the Standard View, while not as simple as the...‘neutral trait’ response, yields many of the same [conclusions]” (3, p. 152). The plain fact is, I argue, that ID is harmful to well-being in the vast majority of cases. Its impact is always (or almost always) bad, even though that badness varies due to biological impairment, individual temperament and social setting. Campbell and Stramondo show that the negative impact of ID is complicated but they do not show that ID typically has no negative impact at all. We can, then, generalize about ID: in all (or almost all) cases it results in disadvantages which lower quality of life even though we may be unable at times to say how much and in what specific ways.

In what follows I argue that as a general rule ID is bad for people who have it; in the vast majority of cases they are harmed, but to varying degrees. ID is:

  1. objectively bad – it brings real disadvantages and reduces quality of life;

  2. instrumentally bad – it causes intrinsic bads and prevents intrinsic goods of life;

  3. globally bad – it lowers a person’s well-being overall, not just in some domains but across a wide range of circumstances;

  4. comparatively bad – it makes a person’s life worse than it would have been without ID.

ID, however, is not

  1. overridingly bad – most ID is compatible with many goods of life and does not ruin life on the whole.

Most ID, to use Tom Shakespeare’s (7, p. 224) words, is neither irrelevant nor tragic. My view should not be misunderstood. First, the fact that ID is bad does not mean it is tragic. I do not wish to perpetuate widely held but simplistic assumptions about the kind of life a person with ID experiences. I do not want to add to unexamined social stereotypes of ID by painting it as poor quality of life – as a tragedy – when it is not.[2] But nor do I wish to pretend that ID is irrelevant – like being left-handed – when it is not. Second, the fact that ID is bad (because it makes a person unable to do typical things and thus hinders flourishing) does not mean that people with ID are morally inferior or less worthy of respect. There is an important difference between devaluing a trait (a man’s cruelty) and devaluing a person (the man himself); and there is an important difference between devaluing David’s PVL and devaluing David.

In sum, I affirm what Campbell and Stramondo deny, i.e., that “it is generally true that life without ID involves higher well-being than life with ID” (3, p. 161). I defend what they claim to have refuted, i.e., that “having ID tends to be bad for a person” in the vast majority of cases (3, p. 162). Where they assume that the Standard and Complicated Views cannot both be true, I see no logical conflict between them. The impact of ID on well-being is both definite (its effect is always negative and so the Standard View is true) and complicated (its negative effect varies and so the Complicated View is true). Individuation does not rule out generalization.

The Nature of Well-being

My argument assumes a particular view of well-being. I adopt an essentialist species conception in which human flourishing consists of a bundle of basic goods such as personal relationships and meaningful activity which are given in human nature. Particular natural functionings, such as mental abilities, make these goals possible.

Dan Brock (9, p. 70) defines well-being (or quality of life) as “an overall assessment of how good a person’s life is, one that includes the person’s own subjective assessment of or happiness with his [or her] life as well as objective components such as accomplishments, personal relations and self-determination, including having the reasonable array of opportunities that self-determination requires.” Subjective well-being is based on a person’s mental states: hedonist theories define well-being as the presence of positive experiences and desire-fulfillment theories define it as the satisfaction of properly formed preferences. Objective well-being is based on a person’s life situation: substantive list theories define well-being as achievement of important elements that constitute a good life.

Like many philosophers, I reject subjective accounts – well-being is not a purely psychological phenomenon. It requires, in addition, the fulfillment of human needs and the exercise of human capacities – the achievement of valuable activities and states of being, not just pleasant mental experiences. Human flourishing consists in a set of goods such as knowledge, accomplishment and relationships. These are constitutive components of a good life, and a person’s life goes better objectively if it includes more of them and worse if it has fewer.[3] If life can be good, then it can also be bad when key dimensions are missing. We are social beings, so social isolation is bad; we are creative beings, so routine mindless work is bad; we are physical beings, so pain is bad (10,11). This does not mean that all natural functionings are necessary to have a decent life. It is good to have partners and children, but people with autism, for example, can live well without romantic relationships. While there is no single recipe for well-being, there are common elements of a good life. “Different people flourish differently,” Jonathan Glover (12, pp. 95–96) states. “A plausible account of flourishing is unlikely to have one blueprint. Instead, there will be different ingredients variously combined.” Yet “underneath all this variety there is also some degree of deeper unity.” Since human beings all belong to the same species, well-being is basically similar for everyone. To repeat: while not all functionings are necessary for a good life (e.g., being able to manage money independently may not be), the more basic abilities that are compromised, the more well-being is decreased.

Life satisfaction is necessary for well-being since we cannot flourish without being happy. But pleasant mental experience is not sufficient for well-being – non-mental conditions of life are also necessary. As Glover (12, p. 95) says, there are two strands to a good life: happiness (a subjectively contented life) and flourishing (an objectively rich-in-human-goods life).

Two Arguments for Why ID is Generally Bad

Before addressing Campbell and Stramondo directly, let me explain why all ID has a negative impact on well-being.

The ID Harm Chain Argument

Consider this chain argument that moves from profound ID to mild ID and concludes that all ID is disadvantageous.

  1. Profound ID is bad. Vicky’s ID disrupts basic elements of her well-being.

  2. If profound ID is bad then moderate ID is bad. David’s ID is bad for the same reason as Vicky’s – it disrupts his well-being, but to a lesser degree.

  3. Therefore, moderate ID is bad.

Now consider Tim, David’s friend with mild ID. Tim can be independent for several hours at a time, rides the bus alone and works a janitorial job with minimal supervision. But he requires oversight with many aspects of life: medication, money, literacy.

  1. If moderate ID is bad then mild ID is bad. Tim’s mild ID is bad for the same reason as David’s – it disrupts his well-being, but to an even smaller degree.

  2. Therefore, mild ID is bad.

Now notice:

  1. If profound, moderate and mild ID are bad then all ID is bad.

  2. Therefore, all ID is bad.

Because the argument reiterates, we can draw a broad, general conclusion about the negative impact of ID – variable as it may be – on quality of life.

Campbell and Stramondo grant that a child with Tay Sachs Disease may be better not being born at all (3, p. 165 and 168). And so they should allow that profound ID disadvantages Vicky by interfering with life activities that are central to flourishing. But then it follows, by extension, that David’s, and even Tim’s, ID negatively impact well-being. The reasons for thinking that profound ID is bad generalize to all ID: it impedes achievement of important goods, to varying degrees, but always negatively. This contradicts Campbell and Stramondo’s view that we cannot generalize about the badness of ID.

It might be objected that the argument, by repeating again and again, slides down a slippery slope. After all, if mild ID is bad then low normal intelligence is bad. Ron Amundson (13, pp. 106–107) points out that because intellectual abilities are scalar properties, not binary ones, there is no sharp distinction between typical and atypical function. “There is a great range of functional variation among humans... The variation is so great, and so multidimensional, that the belief in an objective dividing line between normal and abnormal” is untenable. The boundaries are indistinct, fuzzy and hard to judge.[4]

True: cognitive abilities come in a wide range and there are vagueness worries concerning categories of intellectual function. But this does not mean that there is no reality to the ability/disability distinction, only that it is a standard sorites paradox. While many concepts are vague and distinctions between categories difficult to make, we can and do draw definite lines between things on a continuum. There is a difference between a large heap and a small pile of sand, even though no tiny change is sufficient to make the difference. As Tony Hope (15, p. 73) says, “the precise drawing of the line is arbitrary, but it is not arbitrary that a line is drawn.” While there are no precise cut-off points that define the threshold of typical intellectual functioning, and while we may have trouble classifying borderline cases, there are clear differences between the abilities of Sarah, David and Vicky. Buchanan and colleagues (14, p. 122) point out that the line between typical and atypical intellectual abilities is, for the general run of cases, uncontroversial and ascertainable. Vagueness and indeterminacy do not threaten the distinction between intellectual ability (within a normal range) and disability. While the decision to draw the line of normality at some precise point is arbitrary, the distinction between average intellectual abilities and severe ID is not arbitrary.

It might also be objected that the conditionals stated in the chain argument are false. If we can draw a clear line between Vicky’s profound ID and David’s moderate ID, then premise 2 is inaccurate; and if there is a definite distinction between David’s moderate ID and Tim’s mild ID, then premise 4 is incorrect as well.

True: there are qualitative differences between profound, moderate and mild ID. Dan Wikler (16, pp. 187–190 and 195) suggests two conceptions of ID: on neither theory are the conditionals faulty. On the one hand, we might think of mental abilities as scalar properties (relative, more-or-less attributes). Intellectual capacities occur on a hierarchy or sliding scale; there is a wide array of competencies, and a person has intellectual abilities in degrees that can be compared to others. David has less capacity than Sarah but more capacity than Vicky. Tim’s mild ID has a smaller disadvantage and Vicky’s profound ID a greater disadvantage than David’s moderate ID. But all are disadvantaged compared to Sarah. On the other hand, we can think of mental abilities as binary properties (non-relative, absolute attributes) that one either possesses or lacks. There are only two categories: however vague and uncertain the boundary, some people have impaired mental abilities and others have unimpaired mental abilities. Intellectual abilities are a ‘range property’ which is possessed equally by everyone who has or lacks them. All persons above the threshold equally possess typical mental abilities (all are haves, even if some have more and others less) and all below equally lack typical mental abilities (all are have-nots, even if some lack more and others less) – an IQ of 70 is often taken as the cut-off. I assume that there is a threshold below which it is very problematic to have limited cognitive capacities. This does not mean, however, that above the baseline ID has no negative effects. All passing students in a class are above a grade of F, but there is a significant difference between the bare knowledge of a D student and the excellent understanding of an A student. In the same way, a certain range of cognitive capacity is compatible with a meaningful life, while below that a person lacks what is necessary for one. People with mild and moderate ID fall with the livable range; people with profound ID may not. While both Sarah and David have the mental abilities necessary for well-being, their functioning differs significantly (just like students earning As and Ds both pass, but their knowledge and skills differ greatly). These considerations support the conditionals in premises 2 and 4.

The chain argument suggests that Campbell and Stramondo are mistaken, that we can make generalized judgments about ID and its effects on well-being.

The Troubling Implications Argument

Peter Singer (17, p. 165) says that the idea that disability is bad “is the only way to make sense of actions that we all take for granted”, like the banning of drugs that cause impaired births. “If we really believed that there is no reason to think the life of a disabled person is likely to be any worse than that of a normal person, we would not have regarded the use of thalidomide by pregnant women as a tragedy... The children would merely have been ‘different’... If this sounds grotesque, that is only because we are all in no doubt at all that it is better to be born with limbs than without them.” The same goes for ID – it is better to be born with typical intellectual function than without it.

No true theory can entail things that make no sense, so reductio arguments raise real problems.

  1. If ID is not a harm that makes a person worse off, then it is permissible to cause it. Nothing bad happens when a pregnant woman cognitively disables her healthy fetus with fetal alcohol syndrome by drinking.

  2. If ID is not a harm that makes a person worse off, then it is unnecessary to prevent it. Suppose David’s PVL was caused by changes of blood flow to his developing brain somewhere in the third trimester of gestation due to uterine infection, vaginal bleeding or inflammation of the umbilical cord. If we could treat these conditions and prevent his PVL we need not do so, just as we do not try to stop the birth of left-handed babies.

  3. If ID is not a harm that makes a person worse off, then it is not important to remove it. If David’s PVL is not bad, then I have acted in an unjustified way and wasted scarce resources in mitigating its effects through speech, physical and occupational therapies.

Since we have reason to think that causing any ID is bad and that curing any ID is good, we have reason to think that ID is a real loss that reduces overall well-being in the vast majority of cases. This undermines Campbell and Stramondo’s claim that no true generalizations about the negativity of ID can be made.[5]

Why ID is Essentially Bad

The Americans with Disabilities Act defines disability as a physical or mental impairment that substantially limits at least one major life activity (23, p. 72). ID restricts, in a non-trivial way, a person’s ability to perform general life tasks because the mind is unable to do things typical of human beings. The World Health Organization says that ‘disability’ is “an umbrella term, covering impairments, activity limitations and participation restrictions. An impairment is a problem in body function or structure; an activity limitation is a difficulty encountered by an individual in executing a task or action; while a participation restriction is a problem experienced by an individual in involvement in life situations” (23, p. 60). These definitions imply (but do not entail) that by limiting opportunities, ID lowers quality of life and causes significant and lasting disadvantage.

Brock (9, p. 108) states that “serious disabilities...by definition, typically reduce a person’s quality of life.” Someone with ID is always worse off than a similar unimpaired person. Barnes (5, p. 11) objects that this begs the question: “it should not be built into the very definition of disability that disability is something that’s bad or suboptimal.” Harm is, however, essential to the concept of ID: ID and some degree of disadvantage always go together. As Stephen Wilkinson (24, p. 63) says, “there is an a priori connection between disability and welfare... Characteristics only get to count as disabilities, as opposed to mere differences, if they impair the capacity to flourish.” Two conditions are individually necessary and jointly sufficient for a cognitive trait to constitute an ID (25,26). It must be

  1. a deviation from typical intellectual functioning.

  2. that reduces well-being.

The factual element is an empirical judgment about mental malfunction (it is an inability to perform activities in the normal range for human beings) and the value element is a normative judgment that the malfunction is bad (it causes difficulties in living and thereby worsens a person’s life). The factual condition is not sufficient for a trait to be a disability. Some deviations from typical functioning (like being left-handed) are not disadvantageous, and if there are no disadvantages to a trait then it is mere difference, not disability. Nor is the value condition sufficient for a trait to be a disability. External conditions that reduce well-being (like racism or sexism) are not disabilities; if there are only social disadvantages to a trait, then it is injustice, not disability.

It might be objected that this definition slips from description to evaluation. True: it does, but does so legitimately. ID reduces functioning – that is what a disability is. Because ID reduces functioning, it would be better, all things being equal, not to have it. And it would be better not to have it because ID reduces well-being. There is, then, a necessary conceptual connection between description and evaluation; both factual and value conditions are essential for disability.

The conceptual argument indicates that ID is by definition bad:

  1. If a trait is a disability, then by definition it deviates from typical human intellectual functioning and reduces well-being.

  2. ID is a disability.

  3. Therefore, ID deviates from typical human intellectual functioning.

  4. Therefore, ID reduces well-being.

The factual condition relies on the notion of typical function. Intellectual abilities are biologically determined. Human beings are members of a species – a natural kind – that has evolved with brain structures and mental process that have particular functions which are necessary for the survival and flourishing of the individual. For the mind to function properly is for it to carry out the jobs – thinking and choosing – that it is meant to perform. ID is not simply an invented category: it is a state of reality involving real deficiencies in human powers, when structures and processes do not work as they should. As Hans Reinders (27, p. 56) puts it: “since there is a ‘normal’ functioning for human minds...it follows that, when your...mind...[is] functioning ‘abnormally,’ then you are disabled.”[6]

The value condition asserts that in order to constitute disability, atypical functioning must make a person worse off. Flourishing varies by biological species: what it means to live well is determined by the kinds of beings we are. The constituents of human well-being fulfill important aspects of human nature. “Among the things needed for a good human life,” Glover (12, p. 11) says, “are [various] mental capacities.” Cognitive function enables the personal relationships and productive activities which are central elements of a flourishing life.

ID is a malfunction that prevents the achievement of vital goals which are either components of or prerequisites for a good life (30, p. 52). Given his cognitive limitations, David cannot engage in many activities necessary to live well. Vicky is so disabled as to lack the minimal capacities for a meaningful life: self-consciousness, reasoning, self-motivated activity and language. Intellectual abilities make flourishing possible; because it impedes or prevents human goods, ID is bad. [I acknowledge my limited experience with profound ID and recognize that it is difficult to determine the dividing line between livable and non-livable conditions. Eva Feder Kittay (31, p. 403) claims that “most severely retarded people...can be and are involved in activities and relationships.” Her daughter Sesha with profound ID has a definite personality – she responds to her environment, has relationships and enjoys classical music.]

People with ID should not, of course, be defined solely by their deficits. Despite his impairments, David has significant abilities and enjoys many goods of life. But I reject the suggestion that David’s PVL is not plainly bad. The fact that he has strengths and talents does not mean that he does not have significant challenges and difficulties as well. Nor does it mean that his abilities offset his disabilities for a net neutral effect on his well-being. David is not differently abled. This euphemism is dishonest: he is disabled. By being nonverbal, a dog is differently abled than Sarah, but by being nonverbal, David is disabled compared to her. His species nature is damaged, the dog’s is not; while the dog can do what dogs typically do, David cannot do many things humans typically do, and these impairments negatively impact his well-being. This is even more true of Vicky, and is also true to a lesser degree of Tim.

Disability is, by definition, an adverse departure from typical functioning. Atypical conditions are either beneficial, neutral or harmful.

  1. If an atypical cognitive condition is beneficial then it is not a disability. Physicist Stephen Hawking, whose exceptional brain had unusually large bundles of nerve fibers connecting its lobes, was not intellectually disabled because his abilities depart from typical functioning in ways that are helpful (32).

  2. If an atypical cognitive condition is neutral then it is not a disability. Being musically intelligent rather than kinesthetically intelligent is a mere difference; my friend Ted who plays numerous instruments but is not athletic is not disabled (33).

  3. If an atypical cognitive condition is harmful then it is a disability. David’s PVL affects him negatively by interfering with opportunities and preventing him from achieving important human goods, and so he is disabled.

ID is a mal function that is harmful; it always has a value connotation as something undesirable. If David’s PVL caused no decrease in quality of life, then it would not be a disability at all. But because it is disadvantageous, it is a disability. So is all ID.

Human flourishing consists in a cluster of goods given in human nature. Mental abilities make these goals possible. As Serene Khader (34, p. 49) says, a person’s life is going well if they are “exercising certain valuable capacities that it is in the nature of human beings to exercise.” Because basic intellectual function is necessary for achieving the human good, cognitive limitations negatively impact quality of life. Campbell and Stramondo’s view that no generalizations about the badness of ID can be made is not plausible.

Why ID is Objectively Bad

Campbell and Stramondo claim that it is false on any account of well-being that ID has a negative impact in the vast majority of cases (3, pp. 152–153). They may be right on subjective conceptions of well-being but are wrong on objective theories.

The Nature of Well-being Restated

As noted earlier, there are two ways to describe quality of life: by subjective enjoyment and by objective achievement. Hedonic happiness is a matter of internal experience (a person’s satisfaction with their life), while eudaimonic happiness involves external standards for a good life (how someone’s life is actually going). Subjective theories of well-being emphasize pleasing sensations and desire fulfillment. Objective theories require participation in substantive goods like worthwhile activities and meaningful relationships. Quality of life has both subjective and objective dimensions, and life satisfaction is not equivalent to flourishing. Well-being – having a life full of varied human goods – requires more than feeling happy.

The Nature of Harm

Personal harm affects a particular individual negatively. Subjective harm is feeling worse or badly off, i.e., experiencing lower life satisfaction. Objective harm is being worse or badly off, i.e., having valuable elements of well-being damaged. Comparative harm makes a person worse off than they would have been under other circumstances. Non-comparative harm makes a person experience or places them in a bad state, a disadvantaged condition involving loss of things that make life good.

To be harmed, Joel Feinberg (35, chapter 1) says, is to have our interests set back. To have an interest is to have a stake in something and to gain or lose depending on the condition of that thing. Any entity with interests has a well-being that can be harmed or benefited. In our network of interests some are more important than others. Ultimate interests are things like writing a novel or traveling the world. Welfare interests – both external welfare interests like financial resources and internal welfare interests like mental abilities – are the necessary means to ultimate goals, the basis of a good quality life. When they are damaged a person is very seriously harmed because their entire set of interests is diminished, if not defeated. John Rawls (36, p. 93) states that primary social goods (liberties, opportunities and wealth) are resources that all people need: “whatever one’s system of ends, primary goods are necessary means” to their realization. In the same way, primary intellectual goods are also universally necessary for flourishing – basic human functions and capacities are valid for all persons.

The Deprivation Argument for ID Harm

The argument for the objective badness of ID is simple and intuitive. Suppose, Thomas Nagel (37, p. 181) says, “an intelligent person receives a brain injury that reduces him to the mental condition of a contented infant, and that such desires as remain in him can be satisfied by a custodian, so that he is free from care. Such a development would be widely regarded as a severe misfortune...for the person himself.” Even though he experiences no transition costs and is subjectively content with a full stomach and a dry diaper, the deprivation in what he can do makes it objectively bad. Because “disability substantially limits a major life activity,” Brock (9, p. 75) says, it “closes off an important area of functioning, and the activities that such functioning makes possible, even if the person may not ‘miss’ them.”

ID affects essential psychological capacities necessary for living well. The burden of ID – the harms and disadvantages it involves – depends on its severity. Professional organizations identify four categories of ID – mild, moderate, severe and profound – using severity codes based on functional limitations and intensity of needed supports.[7] Because ID traits come in degrees, so do the resulting harms, as measured by the amount of objective well-being lost: mild conditions are mildly bad while profound conditions are profoundly bad. But all are bad, just not equally bad. This undermines Campbell and Stramondo’s claim that we cannot generalize about the negative impacts of ID.

It might be objected that well-being is entirely subjective and that since people with ID report good quality of life, ID is not harmful. An established body of evidence finds that people with disabilities are about as happy, on average, as people who do not have disabilities (40). Brian Skotko’s (41) research team, for example, found that 99 percent of people with Down syndrome are happy with their lives. So is David: the fact that he cannot care for himself, make life choices or function independently does not mean that he is unhappy.

True: people with ID usually experience satisfying lives. But this does not mean that ID is not bad. Subjective life satisfaction is only one aspect of overall well-being, and so the fact that people with ID report being happy does not mean that ID is not disadvantageous. Because subjective well-being and objective well-being differ, evidence for one is not evidence for the other: as in Nagel’s scenario, a person’s quality of life can be subjectively good and at the same time objectively diminished. We cannot infer that ID is not bad from the fact that people with ID have meaningful lives.[8]

While ID may not lower subjective quality of life, it almost always reduces objective quality of life. Intellectual abilities are not an irrelevant trait like being left-handed – because they are indispensable for achieving valuable human goods, ID is an objective disadvantage in the vast majority of cases even if it does not create subjective distress.

Why ID is Instrumentally Bad

By understanding why intellectual abilities are instrumentally good, we can see why ID is instrumentally bad. Intellectual abilities are personal assets that facilitate well-being. Just as people need external resources (like income and wealth) in order to flourish, so we need internal resources (like cognitive functions) to flourish. Intellectual abilities produce quality of life by supporting a normal opportunity range and wide array of life choices.

ID is instrumentally bad because it causes intrinsic bads and prevents intrinsic goods. People with profound ID like Vicky are incapable of controlled movement, thought, speech and self-awareness; some never walk, talk, think, eat, see or hear. Very low functioning makes her permanently infantile and undermines her flourishing. People with moderate ID like David are also prevented from obtaining important goods of life. Being non-verbal, David has difficulty labeling feelings and expressing thoughts, which he finds frustrating. He does some signing and vocalizing, and he uses a tablet with a chat app for voice talk. These tools give David some ability to communicate but there are many times when he remains trapped in his own mind, unable to get his message across.

Campbell and Stramondo claim that ID only cuts off some avenues for achieving human goods – it does not cut off all avenues to their realization (3, pp. 157–158). While goods like communication can be achieved in multiple ways, however, the ways that David has to communicate are not as good as the ways he lacks. His communication is often barely adequate: even basic messages are limited, and he has no ability whatsoever to express complex or abstract ideas. So, while David’s PVL does not entirely cut him off from the good of interpersonal communication, it does significantly limit it; and since communication enriches life in numerous ways, being non-verbal disadvantages him. His life is worse because he cannot form thoughts properly and communicate them effectively. This is true not just of David but of many people with ID.

Campbell and Stramondo deny that intellectual abilities are a basic component of well-being (3, p. 156). It is true that mental capacities are not direct elements of well-being like activities and relationships are. But they are direct prerequisites – possessing and using them is indispensable if a person is to live well. There is a close connection between intellectual functioning and human flourishing. Vicky’s profound ID is bad because it ruins the mental faculties necessary for pursuing human goods, which are simply not (or barely) available to her. The same reasons that make Vicky’s ID instrumentally bad for her also make David’s ID instrumentally bad for him. This goes for all ID. We can, contra Campbell and Stramondo, generalize about the negative impact of ID on instrumental well-being.

Why ID is Globally Bad

Intellectual abilities are instrumentally valuable for all human beings, not just for particular individuals; they are useful for all plans of life, not only for particular aims. An ID like David’s does not just limit one specific function but disrupts many basic functions. Consider the difference between a general-purpose workshop tool like a flat-head screwdriver that can be used to perform many tasks (tightening and loosening screws, acting as a lever, a crowbar, a punch, a chisel) and a single-purpose tool like a basin wrench used for only one task (removing and installing the nuts that hold a faucet onto a sink). Intellectual abilities to think, plan, choose and communicate are – like the primary good of financial resources – general-purpose capacities necessary to pursue major life activities. ID limits these capacities and lowers overall well-being, not just one domain of well-being.[9]

Intellectual abilities differ from specific abilities (like musical intelligence) whose value depends on particular plans of life which only some individuals desire. ID is not a relative harm like being tone deaf, which might disadvantage a musician but not an athlete. Instead, the loss of intellectual abilities is bad in all lives and for all persons. Intellectual abilities are necessary conditions for living any good human life and for any of the diverse plans of life people might pursue. They apply to every person and are – as Martha Nussbaum (43, p. 252 and 266) puts it – a “human constant” which play an “architectonic role” in life by supporting and suffusing all other functions. David’s PVL prevents the realization of many basic goods as well as higher order goods that are typical of mature adults.

It may be objected that we cannot infer a general conclusion about a person’s well-being from deficits in specific abilities (31, p. 301). David cannot do particular things like drive a car because he has ID. This inability is, at most, a local bad. I cannot pilot an airplane, yet the fact that I lack this specific talent does not reduce my well-being.

True: but we can infer a general conclusion about well-being from deficits in primary functions. David lacks general-purpose abilities like reading and speaking. He has difficulty thinking, planning, choosing and communicating, and these limitations undermine his ability to achieve an entire range of life goals. David’s lack of basic intellectual abilities is globally bad because it negatively impacts a whole set of interests that constitute flourishing (just like abject poverty is globally bad for a person).

People with ID often cannot meet their own basic needs, perform in important domains of life or maintain deep relationships. This is because ID interferes with two sets of general-purpose abilities. According to the American Psychiatric Association (44), ID is defined by deficits in intellectual functioning (reasoning, problem-solving, planning, judgment, abstract thinking and academic learning) and adaptive functioning (activities of daily life such as communication, social participation and independent living).

Executive functions are mental skills that enable individuals to control thoughts, emotions and actions – to pay attention, organize, plan and self-monitor – and thus to manage life tasks of all types (45). These skills include working memory (being able to keep information in mind and use it in some way), cognitive flexibility (being able to think about something in more than one way) and inhibitory control (being able to ignore distractions, regulate emotions and keep from acting impulsively). Adaptive behaviors are skills necessary to meet the demands of everyday living (46–48). A person with deficits in these conceptual, practical and social skills needs significant support and assistance to succeed. Key areas are self-care (dressing, grooming and feeding oneself), communication (understanding and using language), self-direction (problem-solving, initiating and planning activities), social (making friends, maintaining relationships, understanding emotions, social cues and basic moral values), leisure (participating in personal and community activities), home living (housekeeping, cooking, doing laundry), functional academics (reading, writing, math), community use (shopping, using public transportation and services), work (maintaining employment, responding to supervision, cooperating with coworkers, being reliable and meeting work standards) and health and safety (being able to protect oneself and respond to health problems). Limited executive function and adaptive behavior are defining features of ID – and the disadvantages they cause are global, not local. They affect the totality of a person’s life.

It might be objected that David need not meet sophisticated goals like college, career and marriage in order to flourish. True: but his inability to meet his own elementary needs compromises his well-being. Because of deficits in skills of daily living and self-management, he requires direct supervision, regular prompts and simplified routines. David has poor task completion and problems following all but easy instructions; he has trouble with organization and planning, with solving problems and good judgment, with setting goals and completing tasks. The absence of these general-purpose skills has negative consequences on his well-being, and not just on one aspect of his life but across multiple environments and all spheres of activity.

Campbell and Stramondo acknowledge that ID may be a local bad which reduces well-being in some aspects of life. But to label it as a global bad that makes life go worse in all dimensions is reductive synecdoche – a general, negative assumption about a whole human person on the basis of one characteristic (3, p. 162). They are wrong about this. ID causes what Christopher Riddle (49, pp. 81–85) calls “corrosive disadvantage”, i.e., disadvantage that negatively impacts not just one valuable function, but the securing of many valuable activities and states of being. Because intellectual abilities are basic prerequisites for other capabilities, ID affects every aspect of a person’s life and creates, Christopher Boorse (23, p. 56) says, “whole-person impairment.”

It might also be objected that the argument proves too much since many people in the average intellectual range are deficient in general purpose skills like planning and task completion. True: there are many such individuals. But while they may have a good quality life, their lives may be worse because of these deficits, especially if they run into repeated problems with work and relationships. Rather than capturing too much, the argument suggests that correcting stupidity, where possible, is always desirable.

Cognitive resources have a place in every life and play a crucial role in the pursuit of any life plan and so ID has a negative impact not just on a narrow set of life plans but on all life plans. It affects a person in the broadest of ways, not just in some particular aspects. ID is more than the local bad Campbell and Stramondo allow – it is a global bad that reduces well-being overall and on the whole, across a broad range of domains.

Why ID is Comparatively Bad

ID is bad because it sets back interests and compromises welfare. The concept of harm as reduced well-being is counterfactual: a person is harmed in a given situation if there exists some alternative situation where they have more well-being. If ID not been present, then the person’s quality of life would be higher and so ID makes them less well off than they would be without it.

Campbell and Stramondo deny that people with ID are comparatively worse off in the vast majority of cases (3, p. 161). They do, however, identify three factors which explain why the average person with ID has a lower level of well-being than the average person without ID: “very harmful disabilities (those causing severe chronic pain and/or an early death) and transition costs that often accompany the acquisition of disabilities” – as well as “disability-unfriendly social environments” (3, pp. 170–171). If the presence of these conditions and settings make ID comparatively bad then, by implication, in their absence it is not bad. Since David’s ID is neither severe nor acquired—and if he lived in a social utopia – he would not be worse off with than without PVL. I agree that David’s well-being would be worse if his ID was severe or acquired and is worse than it need be because of inadequate social services. But I deny that in the absence of these factors he is no worse off than Sarah.

To argue that ID is comparatively bad requires comparing a person’s actual and counterfactual well-being. The deprivation argument shows that life without ID is preferable to one with ID.

  1. A fully functional adult – Sarah – becomes disabled in an accident that reduces her mental abilities to the level of a 4-year old. She does not know it. She is perfectly happy all day long playing ‘Go Fish’ even though she is unable to exercise human talents and pursue meaningful activities. Did something bad happen to her? The answer is yes; she is deprived of the experiences, projects and activities she could do if not ID. We compare the real Sarah against an imaginary Sarah* who was not hurt in the accident, and the gap between them constitutes the deprivation of objective well-being she suffers. Sarah misses out on the life she would have had had she not been disabled, and something bad happens to her even though she does not experience it as bad. While she is equally happy subjectively, her quality of life is worse objectively.

Now take a parallel story.

  1. A person – David – is born with ID and never functions, even when full grown, beyond the level of a 4-year old. He cannot read, write, count or think, but is not aware of the disadvantages. While unable to pursue significant activities, he is completely content. Did something bad happen to him? The answer once again is yes; he is deprived of the things he could do if not ID. As with Sarah, we compare the real David against a hypothetical David* who was born without ID and the gap between them constitutes the loss of objective well-being. The objective quality of his life could be better even if his subjective satisfaction remained the same.

If ID is neutral and not detrimental to flourishing, then nothing bad happens to Sarah (who should be indifferent between remaining as she is now and becoming ID) or David (who should toss a coin if the Disability Fairy gives him, before birth, the choice of life with or without PVL [5, pp. 67–68]). But these implications are absurd.

It may again be objected that empirical evidence demonstrates that people with ID do not suffer poor quality lives but enjoy good quality lives. It is easy to catastrophize ID as bad quality of life. But the assumption that people with ID cannot flourish because they do not function typically is based on incomplete information, unfair stereotypes and negative attitudes. Most people with ID have fulfilling lives. Kaposy (22, p. 178) notes that “when researchers ask [them] what makes their lives go well, then tend to discuss the sorts of things in objective list theories, such as friendships, family life, enjoyable and rewarding activities.”

True: people with ID generally have good lives both subjectively and objectively. But the issue in comparative well-being is not whether David has a subjectively good life or even an objectively good life, it is whether he could have had an objectively better life. In all likelihood, he could have. The fact that David has a satisfactory quality of life with ID does not mean that his life would not be better if he functioned typically. It is better to be able to use our minds to read and write and count, to know how to tie shoes and fasten buttons, to verbally express thoughts and emotions, than to be like David with none of these abilities. ID disadvantages him objectively by restricting basic life opportunities, primary components of a good life that most people enjoy. This is why his life would be better without PVL. It is also false that people with ID would be as well off as people without ID in a society that accommodates and does not discriminate. David will never do certain things regardless of social adjustments, even if he can do other things with adequate support. Because the disadvantages of ID are partly due to biological impairments, a society free of injustice will not eliminate the badness of ID.

Campbell and Stramondo resist this argument because of “counterfactual opacity.” Epistemic limitations make it hard to determine the truth of counterfactual claims and so we cannot know that ID is comparatively bad. Since we cannot compare possible alternatives to what has actually happened, we cannot know that life without ID is better than life with ID (3, p. 161). There is no hypothetical David* against whom to compare David.

True: such comparisons are shrouded in mystery. I cannot know that had I been an airline pilot I would have had a better life than I have had as a college professor. And we cannot know that life without ID is better than life with ID if we focus on subjective well-being – Sarah’s experiential quality of life may be no more satisfying than David’s. But I deny counterfactual opacity with respect to objective well-being. Consider reductio arguments again. If I cannot know that life without ID is better than life with ID, then why do I grieve at seeing my friend’s 4 year-old daughter doing things that 26 year-old David will never do: talking coherently, counting to 100, learning to read. Is my sadness based, as Campbell and Stramondo suggest, on “ableist fantasy” (3, p. 161)? Should Vicky’s family not regret her deficits and difficulties? Should I be indifferent to whether Sarah remains fully-abled or suffers a brain injury that, without transition costs, reduces her to David’s level of functioning? And if we cannot know that life with ID is comparatively worse than life without ID, then why is it wrong to disable another person? Suppose Vicky is impaired because, while born cognitively typical, her parents beat her viciously. If nothing bad happened to her, why punish them for a victimless crime that harmed no one? These implications call into question the view that there is nothing comparatively bad about ID in almost all situations. Campbell and Stramondo are right that epistemic humility is warranted, since it is difficult to evaluate counterfactuals. But they are wrong to conclude that no generalizations can be made about the comparative badness of ID. While David has sufficient intellectual capacity to enjoy a good life, he is worse off than Sarah – his life would likely go better objectively with fuller mental abilities.

Campbell and Stramondo also argue that ID is identity-constitutive – it shapes individual identities in substantive ways (3, p. 161). Its removal would involve the destruction of the person: David without PVL is simply not David. Given the non-identity problem, his ID is unavoidable; the only choices for him are life with PVL or no life at all. This analysis is not quite right. Because David’s ID was caused by a contingent prenatal injury he could, in fact, have been born without PVL. This is different from ID due to a chromosomal condition like Down syndrome, where disability truly is unavoidable for the particular person that has it.

True: there is no scenario in which he, the same person, can have a life without ID. There is no phantom non-disabled David* compared to whom David is worse off. But the fact that ID is identity-affecting is irrelevant to whether it is a harm. That David had no other way of getting born does not mean that his PVL is not bad, that it does not diminish his quality of life. That he or Vicky are not harmed relative to any life they actually could have had does not mean they are not harmed simpliciter.

ID is comparatively bad (it makes people worse off) even if not overridingly bad (it does not make them badly off). Life with ID can lack important features without falling below zero on an objective line of welfare. As Anita Silvers (50, p. 54) states, burdensome limitations do not necessarily mean burdensome lives – ID is bad even though life with ID is often good. But, to repeat, this is not the question: the real issue is that people with ID could have objectively better lives without ID. This is why ID is almost always comparatively bad, despite what Campbell and Stramondo say.

Concluding Remarks

Many scholars agree with Campbell and Stramondo’s position. Robert Wachbroit (51, p. 30 and 33) argues that “we cannot state what impact a particular health condition has on well-being. We cannot, for example, determine the effect that diabetes has on well-being, because the impact that [it] has on well-being will vary with the environment. We should therefore be skeptical of . . . quality of life assessments of different health conditions.” The same can be said of Down syndrome or PVL. Shakespeare (7, p. 217 and 224) concurs: “every life is different, so it is dangerous to generalize about the experience of impairment.” He continues: “the creation of a disabled ‘ideal type’ – either as a neutral or benign experience, or as a negative and tragic experience – does not do justice to the complexity and variability of the experience of disability.” Because challenges and disadvantages are individualized, we cannot generalize about the impact of ID on well-being. Garret Merriam (4), too, asserts that the differences in individual and social circumstances make abstract assessment of ID and quality of life difficult. Rather than taking species typical functioning as the standard of flourishing, we should look at whether a person is living well in the particular concrete circumstances of their life. There is no absolute hard and fast relationship between ID and flourishing – we can only consider specific individuals on a case by case basis. Since we cannot generalize about the well-being of a whole class of people with ID, we must reject the blanket assumption that ID is bad. “Are we worse off?” disability rights activist Harriet McBryde Johnson (5, p. 54) asks. “I don’t think so. Not in any meaningful sense. There are too many variables.”

I agree that the relationship between ID and well-being is complicated by multidimensional influences including biological condition, social environment and personal temperament. I agree that we should not exaggerate the disadvantages of ID or simply assume that life with ID is an unremitting tragedy. The fact that something is individualized, however, does not mean that it cannot be generalized. Campbell and Stramondo reason, in effect, as follows:

  1. The disadvantages of ID are individualized.

  2. Therefore, the disadvantages of ID are not generalized.

Their argument, however, assumes the following:

  1. If the disadvantages of ID are individualized then they are not generalized.

This conditional is equivalent to a disjunction:

  1. The disadvantages of ID are either individualized or generalized.

But this is a false dilemma: one possibility does not exclude the other since

  1. the disadvantages of ID are both individualized and generalized.

Aristotle (52, p. 38) posits that wicked “men are...bad in many [ways]” and Leo Tolstoy (53, p. 3) observes that “every unhappy family is unhappy in its own way.” These statements entail two truths: the first is general (immoral people are all immoral and unhappy families are all unhappy), the second is individual (immoral people and unhappy families vary a great deal; each immoral person is immoral in their own way and each unhappy family is unhappy in its own way). The general fact and the individual fact are compatible.

The same is true of ID: every person with ID is disadvantaged but each is disadvantaged in his or her own way. The general fact that all are harmed – there is always a negative score to ID – is not contradicted by the individual fact that the harms vary – there is no single negative score. The disadvantages of ID are definite (all ID is bad) but complicated (its badness depends on multiple factors). It is wrong to think that flourishing is assessed either by universal species essentialism or by particular individual circumstances. Evaluation of ID and well-being involves both: ID is always bad since the functions indispensable for flourishing are given in human nature. But this badness varies with specific life situations that aggravate or mitigate the disadvantages of sub-typical mental functioning. To affirm the latter is not to deny the former.

According to Campbell and Stramondo, there is no ID in general. There is David’s ID and that of his friends Minnie and Adam, Claudia and Steve, Lisa and Ernie; and there are their very different life situations: some work competitive jobs while others attend day training workshops; some live independently while others live with parents or in group homes. Determining how bad ID is and how its disadvantages are influenced by internal and external factors is complicated and so the disadvantages of ID come in varying degrees. But since intellectual abilities are general-purpose means to human flourishing, this broad generalization is also true: ID is disadvantageous – all people with ID are harmed. Because they have difficulty performing key life tasks, ID prevents David, his friends and everyone with ID from enjoying some, often many, important goods of life and so they do not flourish as fully as people without ID.

David’s PVL harms him, limits his attainment of important goods, negatively affects his whole life and makes it worse than if he was cognitively typical. It might be objected that since his ID is objectively, instrumentally, globally and comparatively bad, it must also be overridingly bad. Not true: ID can bring significant disadvantages without destroying welfare – it can reduce quality of life without ruining it. That ID lowers well-being, and may do so pronouncedly, does not mean that it makes life with ID not worth living. A family may be unhappy in important ways without being so dysfunctional that divorce is preferable. As I have stressed, ID can be bad without being tragic.

Finally, it might be objected that my entire position reinforces intelligism, the view that intellectually typical people are morally more valuable, and thus more entitled to life, than people with ID. Simo Vehmas (54, p. 40) claims that such a view is discriminatory in the same way as racism and sexism. The intelligist argument is as follows: “since the life of a normal human being is more full, it is also more valuable than the life of a person with ID.” Put formally:

  1. An intellectually typical life is more full.

  2. Therefore, an intellectually typical life is more valuable.

Vehmas refutes the argument by denying the truth of the premise. It is false that intelligence is a precondition of a happy and fulfilling life and that people with ID have little prospect of a satisfactory or full life. Evidence indicates otherwise. In addition, there is no such thing as a perfect or ideal life. All lives have restricted possibilities, and so people with ID have the same chance of achieving a good life as intellectually typical people do (54, p. 44).

True: there is no such thing as a perfect life. But while my lack of particular musical talents does not affect my well-being, David’s lack of general-purpose abilities does lower his quality of life. Abilities are not all equal – some are more important to flourishing than others. Intelligence, while not the only factor relevant to well-being, is a crucial factor. The things Vehmas (54, p. 45) identifies as elements of a meaningful life – work, hobbies, relationships – do depend on some sort of intellectual competence. While intellectual capacity and well-being do not fall on a straightforward continuum (where more ability means more flourishing), quality of life is in part a function of mental abilities.

I affirm the basic truth of the premise found in the intelligist argument, and have argued, in Vehmas’ (54, p. 47) words, that intelligence can be valued in a way that is not connected with intelligist intuition and does not lead to discrimination against individuals with ID. But I deny the argument’s validity, that the conclusion follows from the premise. As noted earlier, quality of life and moral status are two different things, and lower well-being does not imply inferior human value. Mental properties are irrelevant to moral status: Sarah does not have a stronger right to life than David or Vicky. But intellectual abilities are relevant to quality of life: Sarah does enjoy more objective well-being than David or Vicky. That all three have equal moral status does not mean that they have equal quality of life, nor does the fact that Sarah’s life is more full mean that it is more valuable.

In the vast majority of cases people with typical intellectual function have access to more valuable activities and relationships. ID limits the level of basic activities and roles that an individual can perform and achieve, and so it lowers well-being most of the time. While ID is not usually a tragedy, it is not irrelevant either – it is disadvantageous even if not destructive. While people with ID enjoy subjectively good quality lives, they could have objectively better quality lives if they did not have ID. Campbell and Stramondo are wrong to think that we cannot make a broad generalization about the relationship of ID and well-being. We can generalize (ID is always bad) without overgeneralizing (it is uniformly or terribly bad). As a general rule ID is bad for people who have it. ID always has a negative impact on quality of life even though that negative impact is complicated and varied.