Absences, deficiencies and malfunctions in biological and medical explanations

Symposium: „Absences, deficiencies and malfunctions in biological and medical explanations“ at the Second international conference of the Gesellschaft für Wissenschaftsphilosophie GWP.2016 „Philosophy of Science Between the Natural Sciences, the Social Sciences, and the Humanities“

March 9, 2016, 11 a.m. – 13 p.m.
Heinrich Heine University
Universitätsstraße 1
40225 Düsseldorf

 


 

Aims and Scope:

Absences, deficiencies and malfunctions play an indispensible role as causal factors not only in everyday life but also in many scientific explanations and models, especially in the biological and medical sciences. Thus, molecular biological and neurophysiological mechanisms typically involve not only positive factors, but also the absence of inhibiting or disturbing factors. Many diseases are prima facie caused by the lack of certain substances in the body (e.g., scurvy is explained by a shortage of vitamin C) or by the prevention of processes that are vital to life (e.g., HIV causes death by reducing the number of immunocompetent cells in the organism).

Often, it does not only make a causal difference whether a certain factor has occurred or not, but also to which extent it has occurred, i.e., whether it has exceeded or fallen below a certain threshold. It may be, for instance, that vitamin C has not been completely absent in the body, but that there has not been enough of it, so that the patient developed scurvy. A similar phenomenon located somewhere between the total presence and the total absence of causal factors is the phenomenon of dysfunctions. Dysfunctional processes in a complex system are not ‘nothings,’ strictly speaking – they are processes, after all. Yet, in some quantitative or qualitative respect, these processes fall short of their proper function.

A fundamental question related to the causality of absences, deficiencies and dysfunctions is whether the distinction between what happens or fails to happen and between what is enough or not corresponds to an objective matter of fact, or whether these are distinctions which cannot be accounted for without reference to human expectations, interests or normative principles that are otherwise taken to be alien to the purity of a metaphysical theory of causation. The upcoming workshop is intended to address these and adjacent questions:

· Are there, objectively speaking, such things as negative events, states or processes in biological and medical systems?

· Are negative factors bestowed with causal relevance only insofar as they are focused from a ‘therapeutic’ perspective which aims to fix or remove that which is absent, deficient or disturbing, or may they also be causally relevant apart from such a focus?

· What is the ontological status of biological and medical functions?

· What are the conceptual differences between dysfunction, functional deficit, malfunction, hypofunction, and hyperfunction? Are these differences of ontological and/or medical significance?

· What is the causal relationship between functions/dysfunctions and life/survival/death/early death? Is there a quantitative, measurable or calculable relationship? Is the “amount” of functional deficit a numerical, quantitative magnitude?

· In most cases, one kind of dysfunction – e.g., kidney or heart failure – may be caused by very different causes and may be symptom of very different diseases. Should all these occurrences really count as the same kind of dysfunction, or should they be conceptually differentiated in philosophical analyses?

· Might privations and dysfunctions have explanatory value without being real or without being causal?

· What is the status of scientific explanations that refer to fully or partly negative entities?

 


 

Talks:

Ludger Jansen: „Functions, malfunctioning, and negative causation“

Functional explanations are common currency both in biology and engineering: Causal features of a system part or processes in which a part participates can be explained by reference to its function; system processes can be explained by reference to the functions of the parts of the system. At least some of these explanatory patterns can not only be applied in cases of normal functioning, but also in the case of malfunctioning.

According to a straightforward (though not consensual) analysis, a bearer of the function to F is malfunctioning if and only if it has the function to F but not the disposition to do so.

This makes explanations of malfunctioning peculiarly problematic. First, they seem to be a case of negative causation, as they refer to absent dispositions. Second, this analysis seems to require that the function to F cannot be identical with the disposition to F. But then we seem to be trapped in a dilemma: Either the realm of functions is separated from the realm of dispositions; then functions seem to be causally inefficient. Or functions are identical with dispositions; but then malfunctioning seems to be conceptually impossible.

The paper reviews how the causal, etiological and intentional theories of functions can deal with these problems. In particular, it will discuss how the interdependent distinctions between historical vs. intrinsic features on the one hand and between types vs. tokens on the other hand can be exploited to develop a coherent account of the causal role of functions. While function types are not identical to disposition types, there are important interrelations between functions and dispositions. These will be found (1) in the historical dimension, (2) on the type level, and, (3) maybe also on the instance level: Instances of functions may well be considered also to be instances of dispositions.

 


Thomas Schramme: „The quantitative problem for theories of function and dysfunction“

Biological mechanisms have effects that we deem their function. For instance, the function of the heart is to pump blood. One of the problems of function theory is to draw a distinction between effects that are functional and other effects that do not serve a function. This can be called the qualitative problem of function theory. Obviously, there can be many different accounts as to why an effect is supposed to be a function, for instance based on its etiology, or its contribution to overarching goals of the organism, or for reasons of human interest. Accordingly, these different theories lead to different accounts regarding the normativity of explanations of functions. Some theories of function hold the qualitative problem to be solved by natural science, most importantly by biology and psychology; other theories consider mainly societal interests, for instance regarding medical treatability or enhancability of an organismic process

A second important problem of function theory can be called the quantitative problem. It mostly affects medical science and practice. The problem consists of drawing the boundary between function and dysfunction. For instance, the function of the heart is to pump enough blood to sustain the organism. But how much is enough? There might be too little or too much blood being pumped, therefore two ways of dysfunction are possible. Whether a particular mechanism – a mechanism token, as it were – is dysfunctional, will probably require a different quantitative value in different individual organisms. After all, the amount of blood required to sustain other organismic functions will depend on individual values, such as age, weight, or stamina, as well as environmental factors, such as altitude or temperature. But be that as it may, surely we need generic accounts of proper quantitative function, especially in medicine, hence types of quantitative values. Perhaps these might be more fine-grained in being tailored to different age groups, gender etc. Nevertheless, there seems to be considerable scope for particular interests to influence the quantitative threshold of dysfunction. There are numerous examples from the history of medicine where these thresholds were set or influenced by non-scientific considerations, such as interest in the health of the population (e.g. Body Mass Index) or economic interests of doctors and the pharmaceutical industry (e.g. hypertension).

After setting up the problems for theories of function in the way described, in my paper I will focus specifically on the quantitative problem. I will argue that we can solve this problem in a scientific way, without the need to resort to societal interests or values. Statistics and biological theory are the means to solve the problem. Still, there is the interesting issue of individual levels of quantitative dysfunction. I will end the paper by proposing that the task of identifying tokens of dysfunction is to be performed by clinical diagnosis. After all, diagnosis is an application of typological classification to individual cases. So in medicine the quantitative problem calls for both theoretical and practical expertise.

 


Peter McLaughlin: „Speciesism, Species Norm and the Lack of Species-typical Traits in Moral Argumentation“

One of the most important concepts structuring current philosophical argument in applied bioethics is ‘speciesism’, introduced by Peter Singer as an analogue to ‘racism’ to characterize our privileging of members of our own species in questions of ethics. Wherever claims to moral considerability are based on the possession of particular properties (such as the ability to feel pain, have preferences or experience self-consciousness), the question arises, whether an individual who does not in fact possess such species-typical properties to the species-typical extent can nonetheless still have the claims or rights that ‘normal’ individuals of the species have, based on those traits. The position denounced as ‘speciesist’ maintains that the natural properties used to justify or motivate ascriptions of moral considerability play the same role for all individual species members, independent of how far they deviate from the species norm for those traits. The question arises whether anyone can legitimately speak of dysfunction, disease or handicap without in some sense being a speciesist. Thus, this question points to the intersection of bioethical questions, questions of the normativity of classifications of dysfunction/malfunction or sickness in philosophy of medicine and political questions concerning the purportedly discriminatory nature of the vocabulary of the disadvantaged or handicapped.

This talk will analyze the role of the species norm, type-token distinctions and the function/malfunction distinction in the ascription of claims to moral considerability.