Exploring the boundaries and ontology of Psychiatric Disorders (PDs) using the Homeostatic Property Cluster (HPC) model

In this article we show that, even though the classification and diagnosis of Psychiatric Disorders (PDs) are performed according to essentialist terms, the psychiatric diagnoses currently employed, (i.e., clinical psychiatry) do not actually meet these criteria. Diagnosis is performed operationally. In this paper, we suggest a change of perspective. We reject essentialism relating to PDs and argue for the Homeostatic Property Cluster (HPC) model, which allows a greater insight into the ontology of PDs than the operational perspective. More specifically, we argue that the HPC model allows for a synthesis of continuous and discrete methods of understanding the boundaries between PDs. Finally, we specify in a more general manner, the kind of ontology we deal with when adopting the HPC model, arguing that this model can be viewed as a mirror device, reflecting the ontological features of PDs.

Homeostatic Property Cluster Theory without Homeostatic Mechanisms: Two Recent Attempts and their Costs

The homeostatic property cluster theory (HPC) is widely influential for its ability to account for many natural-kind terms in the life sciences. However, the notion of homeostatic mechanism has never been fully explicated. In 2009, Carl Craver interpreted the notion in the sense articulated in discussions on mechanistic explanation and pointed out that the HPC account equipped with such notion invites interest-relativity. In this paper, we analyze two recent refinements on HPC: one that avoids any reference to the causes of the clustering of properties and one that replaces homeostatic mechanisms with causal networks represented by causal graphs. We argue that the former is too slender to account for some inductive inference in science and the latter, thicker account invites interest-relativity, as the original HPC does. This suggests that human interest will be an un-eliminative part of a satisfactory account of natural kindness. We conclude by discussing the implication of interest-relativity to the naturalness, reality, or objectivity of kinds and indicating an overlooked aspect of natural kinds that requires further studies.

What’s my age again? Age categories as interactive kinds

This paper addresses a philosophical problem concerning the ontological status of age classification. For various purposes, people are commonly classified into categories such as “young adulthood”, “middle adulthood”, and “older adulthood”, which are defined chronologically. These age categories prima facie seem to qualify as natural kinds under a homeostatic property cluster account of natural kindhood, insofar as they capture certain biological, psychological, and social properties of people that tend to cluster together due to causal processes. However, this is challenged by the observation that age categories are historically unstable. The properties that age categories are supposed to capture are affected by healthcare and cultural developments, such that people are staying biologically, psychologically, and socially young for longer. Furthermore, the act of classifying people into age categories can bring about changes in their behaviors, which in turn alter the biological, psychological, and social properties that the categories are supposed to capture. Accordingly, I propose that age categories are best understood as interactive kinds that are influenced in dynamic ways by looping effects. I consider some implications of these looping effects for our classificatory practices concerning age, including how different disciplines may need to review the ways they define and use age categories in their inductive inferences.

Vividness as a natural kind

Imaginings are often characterized in terms of vividness. However, there is little agreement in the philosophical literature as to what it amounts to and how to even investigate it. In this paper, we propose a natural kind methodology to study vividness and suggest treating it as a homeostatic property cluster with an underlying nature that explains the correlation of properties in that cluster. This approach relies on the empirical research on the vividness of mental imagery and contrasts with those accounts that treat vividness as an explanatory primitive and with those that attempt to provide a definition. We apply the natural kind methodology to make several substantive (but also provisional) claims about the vividness of mental imagery. First, we will argue that it forms a homeostatic property cluster, in that it is reliably correlated with, but not defined by, some properties, such as the level of detail, clarity, perception-likeness and intensity. In arguing for this claim, we also show how the cluster can be modified in the light of empirical research by complementing it with a correlation between vividness and familiarity. Second, we will argue that these correlations can be explained by an underlying property at the architectural level; i.e., the availability of stored sensory information for the elaboration of a mental image.

Social Construction, HPC Kinds, and the Projectability of Human Categories

This paper addresses the question of how human science categories yield projectable inferences by critically examining Ron Mallon’s “social role” account of human kinds. Mallon contends that human categories are projectable when a social role produces a homeostatic property cluster (HPC) kind. On this account, human categories are projectable when various social mechanisms stabilize and entrench those categories. Mallon’s analysis obscures a distinction between transitory and robust projectable inferences. I argue that the social kinds discussed by Mallon yield the former, while classifications of biological kinds yield the latter. Classifications from psychiatry (“schizophrenia,” “hysteria”) are discussed as examples.

Cancer

Is cancer one or many? If many, how many diseases is cancer, exactly? I argue that this question makes a false assumption; there is no single “natural” classificatory scheme for cancer. Rather, there are many ways to classify cancers, which serve different predictive and explanatory goals. I consider two philosophers’ views concerning whether cancer is a natural kind, that of Khalidi, who argues that cancer is the closest any scientific kind comes to a homeostatic property cluster kind, and that of Lange, whose conclusion is the opposite of Khalidi’s; he argues that cancer is at best a “kludge” and that advances in molecular subtyping of cancer hail the “end of diseases” as natural kinds. I consider several alternative accounts of natural or “scientific” kinds, the “simple causal view,” the “stable property cluster” view, and “scientific kinds,” and argue that the diverse aims of cancer research require us to embrace a much more pluralistic view.

Definition

There are innumerable attempts at defining ‘religion.’ The need and possibility of defining religion have been challenged, but such claims often presuppose specific definitions of religion and certain definitions of definition. The link between a definiendum (expression to be defined) and a definiens (expression that does the defining) can be conceived of in different manners. Since definiens are intended to express the meanings of the definienda, definitions are theoretically impacted by underlying theories of meaning. A crucial semantic distinction is that between meaning realism (meanings as fully determinate) and meaning antirealism (meanings as indeterminate). Different theories of meaning resonate with different types of definitions (real, lexical, and stipulative). In the study of religion, a recurrent distinction is that between functionalist and substantive definitions. The limitations of both can be overcome by combining them. Homeostatic property cluster definitions are a possible alternative.

Synthetic Biology and Natural Kinds

In the life sciences, biologists and philosophers lack a unifying concept of species—one that will reconcile intuitive demarcations of taxa with the fluidity of phenotypes found in nature. One such attempt at solving this “species problem” is known as Homeostatic Property Cluster theory (HPC), which suggests that species are not defined by singular essences, but by clusters of properties that a species tends to possess. I contend that the arbitrary nature of HPC’s kind criteria would permit a biological brand of functionalism to inform species boundaries, thereby validating synthetic organisms as members of a species that do not belong

The Distinction between Psychological Kinds and Natural Kinds Revisited: Can Updated Natural-Kind Theory Help Clinical Psychological Science and beyond Meet Psychology's Philosophical Challenges?

Philosophers and psychologists have long held that mind-dependent/human (or social) kinds are not natural kinds. Yet in the last three decades philosopher of science Richard Boyd has challenged this belief to widespread acclaim in the philosophy of biology, where the natural-kind status of species taxa has been debated. Boyd proposed that natural-kind status hinges not on a kind's mind independence or on demonstration of its essential properties but rather on whether it supports inductive generalization, in which case it is a “homeostatic property cluster” (HPC) kind. Boyd indicates that any human/mental kind can in principle be a natural kind, without physical reduction of its properties, as long as it constitutes an HPC kind and so can be studied by way of the causal mechanisms that, he theorizes, underlie all natural kinds. In the last decade Boyd's HPC theory of natural kinds has influenced theory of mental disorder kinds and shares commonality with Denny Borsboom's burgeoning “symptom network” approach to psychiatric diagnosis. It therefore warrants more thoroughgoing theoretical and empirical analysis. This article revisits the heterogeneity that inheres in DSM categories and motivated alternative approaches, such as the Research Domain Criteria (RDoC) of the NIMH. Also assessed are two worries about the future of “HPC kinds” of mental disorder kinds: (a) ontological relativism and reification, and (b) epistemic perspectivalism and relativistic knowledge. Though focused on clinical kinds, this analysis has implications for psychological science beyond its clinical subdiscipline.