In this paper, I will show and discuss two accounts of disability, and then I will build a main argument between these two accounts.
First: Boorse account:
Before discussing the loss or the disadvantage Boorse claims that disability -disease- creates, I should first state some notes about the Boorse account.
Boorse in his paper, Health as a theoretical concept (1977), discussed the notion of health and those disadvantages health will interpret he named diseases. Since we are looking for disability, the reader should assume that any disability term in this paper would be disease in Boorse account. In addition, there are some terms, to which Boorse gave specific definitions, which should be stated before discussing his account:
1. The reference class is a natural class of organisms of uniform functional design; specifically, age group of a sex of a species.
2. Normal function of a part or process within members of the reference class is a statistically typical contribution by it to their individual survival and reproduction.
3. Health in a member of the reference class is normal functional ability: the readiness of each internal part to perform all its normal functions on typical occasions with at least typical efficiency.
4. A disease is a type of internal state, which impairs the health, i.e., reduces one or more functional abilities below typical efficiency.
According to the Boorse account, the function in species is the goals that the species in general have in order to survive and reproduce, and the ability to perform these goals. Any case of a function performance under the minimal functional ability of the species design of the reference class would be assumed as disability. First I should define the species design, and mention how it should be chosen. The species design is the main picture of all the biological functions that the reference class is able or ready to conduct in order to achieve the minimal survival and reproduction. These functions, which are included in this design, should be chosen statically from the reference class. It means all the biological functions necessary for a specific species that should be counted as a function of the species design. There are many kinds of loss and disadvantages, which according to Boorse create disability or disease. I will categorize them into four kinds, which will be presented in the paragraphs below.
First, the loss of a function according to the sex and the age.
In order to indicate whether a specific loss in function is a disability or not, we should first decide – biologically – if this function is important to achieve a goal for the reference class or not. It means that we must define the goals of each reference class, and decide which categories of the assigned species are having this goal as a survival function. Therefore, there arises a critical need for separation of the species functions with respect to the age. To elaborate, there are some efficient functions, which are related to age group, as the production of growth hormone in children. Any deficiency in producing this hormone in this age group will raise into a dysfunction, which will affect survival and create a disability. While in adults, this hormone is not produced totally, and this inability is not creating any disability, because growth is not the ultimate goal for this reference class. Another separation is needed in the species in respect to sex. As in the case of age groups, there are some functions, which are related to sex in the same species, such as the production of milk in mammals. If we have a female pregnant mammal that cannot produce milk, we assume that this female is disabled, while if we have a male who cannot produce milk -all of them cannot- then, he is not disabled. Again, this is related to the ultimate goal and the statistical function that the reference class can do. These two examples show the importance of dividing the species into sexual and age groups reference classes, in order to decide, which loss disability creates and under which circumstances.
Second, the inability to achieve the goal because of excessive or poor functioning.
As I mentioned before, by the Boorse definitions, the normal functional ability is performing a function in the best way, not superior or poor. This idea arose because of the existence of cases that have high performance in specific functions, for example, hyperthyroidism. As generally known, thyroid hormone is a regulation hormone in the human body, which must be secretion in a very specific amount. Any increase or decrease in thyroid secretion will create disorder in human body function that will lead to disability. Therefore, hyperthyroidism, which is the massive production of thyroid, and lack of hyperthyroidism are both considered as disabilities. This idea shows that the Boorse account is very strict about the ultimate goal of any function. He was not considering the small goal of each function, but looking for the final goal of the species design, which provides survival of the species. Therefore, even if excessive function were a healthy mark for a small function itself, it would be counted as a disability if it were affecting the ultimate function badly. Nonetheless, Boorse did not consider all excessive functions as disabilities; first the excessive function must defect the ultimate goal to be considered as a disability.
Third, the loss of function because of latent disease.
Latent disease or abnormal cases in a reference class may have no direct effect on performance of any function. More accurately, they can progress for a long time in the human body without being detected, because of their minimal effect on the gross functions of the human body, for example, Hepatic cirrhosis and weak diabetes. However, these diseases do affect the standard tissue functions and defect the efficiency of these parts of human body. Going back to the normal function definition, any function that provides minimal survival and statistically occurs in species design must be counted as a normal function, and any loss in it will be considered as a disability. Therefore, even if these diseases are not directly affecting the survival of the human being, but have latent effect, they should be considered as a disability.
Fourth, the disability because of the loss of readiness.
According to Boorse, any inability to conduct a function is a disease, even if the occasion, in which there is a need of conducting the function, does not arise. It means that a disability to Boorse is not the inability of conducting a function when individual needs to, but the disability is the inability of conducting a function that the individual may need in the future according to the species design. For example, in the case of the king in Africa, who cannot move his legs to walk because of an accident, but in this country the king should not walk because he has slaves, who are carrying him all the time. Still, according to Boorse, this king is disabled because he does not have the readiness to conduct this function. Another example is a monk who has impotence and cannot have sex because of biological causes, but he is still a monk, which means he does not need to have sex. However, Boorse claims that this monk is disabled because he is not ready to conduct a normal statistical function, which is having sex. Therefore, even disadvantages of readiness of conducting functions will create disability.
Second: Nordenfelt disability account.
Before going in depth with Nordenfelt account of disability and what causes disability from his point of view, we should state the base of the ability, on which Nordenfelt founded the definition of disability. According to Nordenfelt, any ability can be analyzed based on three factors: the agent – the one who acts, the goal of an action, and the circumstances, in which the agent acts. Any loss of these three factors will be an inability in Nordenfelt account. However, he claims that not all inabilities are disabilities; just inabilities of conducting vital goals are assumed as disabilities.
As for the definition of vital goals, they are the goals that are necessary to provide the individual with at least the minimal happiness in the long run. Therefore, all biological goals that achieve the minimal survival and reproduction are vital goals for almost all people. It means that any inability of conducting one of these goals will be a disability. Moreover, not just the survival and reproductive goals are vital, but also any goals that an individual thinks are important to conduct and inability to achieve it will be assumed as disability.
Moreover, there are some disabilities, which are related to the circumstances, in which the agent acts. First, let us divide the circumstances into internal and external. Internal circumstances are related to the biological and somatic abilities, while external are related to the cultural abilities. So, any inability in these circumstances that is related to the vital goals will be assumed as disability.
Boorse, C. (1977). Health as a theoretical concept. Philosophy of science, 542-573.
Nordenfelt, L. (1993). On the notions of disability and handicap. International Journal of Social Welfare, 2(1), 17-24.