What Does It Mean for a Body (part) to Fail?

I just published a new paper:

Barandiaran, X. E. (2025). Organizational Accounts of Malfunction: The Dual-Order Approach and the Normative Field Alternative. Biological Theory. https://doi.org/10.1007/s13752-025-00500-z

Why does a heart attack count as a malfunction, but a volcanic eruption doesn’t? What makes one failure meaningful while the other is merely an outcome of physical laws? This is a foundational question in philosophy. It conditions the nature of explanations in philosophy of science, the autonomy of biology, the concepts of adaptiveness, health or well-being, the possibility of meaning emerging in nature, or, ultimately, our own judgement.

At the most basic level, at the heart of biological explanation, lies the idea of function. Your heart functions to pump blood; your kidneys function to filter it. But the idea of function implies something deeper: that things can go wrong. If a function can succeed, it can also fail.

“There is no function if there is no room for failure or possibility of malfunctioning, otherwise the notion of function would add nothing to the mere description of a process,” (p. 2)

There are different accounts of (mal)function in the philosophical pool. Most classical theories of function fall into two camps: biostatistical and etiological. The first (Boorse) defines dysfunction as statistical deviance from the norm. The second (Millikan, Neander) grounds function in evolutionary history—traits fail if they don’t do what they were selected to do. An alternative to these accounts is the so-called organizational account. It states that a trait malfunctions when it fails to contribute to the self-maintenance of the system it belongs to, in the manner that other parts dynamically (functionally) presupposes it to do so. I have been discontinuously working on this theory since my MSc thesis (2002), then with Alvaro Moreno (2008), then with Ezequiel Di Paolo and Marieke Rohde (2009), and lastly with Mattew Egbert (2014).

The canonical definition of the organization approach to function is due to Mossio, Saborido and Moreno, to be latter reframed in Moreno and Mossio’s book “Biological Autonomy” in 2015. This paper is somehow a (very) late response to some problems inherent on their specific understanding of malfunction. I have named it the “dual-order” approach because it defines malfunction as a failure of a trait to respond to a regulatory command to switch between “regimes” of self-maintenance. I suggest we need to take a different route (advanced and formalized in Barandiaran and Egbert 2014). My alternative does away with the need for two orders of norms, and proposes a gradual (non-binnary) account of function. It analyses malfunction dynamically, in terms of how a trait’s activity aligns with what is minimally required for maintaining viability. I use the concept of a “normative field”—a gradient that specifies, at each point, how a variable (like heart rate or food intake) needs to change to avoid system collapse.

“A trait operates normatively when its effects on the viability space correlate positively with the normative field”. (p. 8)

With this approach, it is possible to distinguish between different types of dysfunction (see figure panel d):

• Subfunction: the trait works, but too slowly or insufficiently.
• Malfunction: the trait works against what’s required.
• Nonfunction: the trait fails to operate at all when needed.

Fig. 2 Bifurcation diagram of a system, depicting the incoming food concentration [F] on the x-axis and the amount of internal metabolite concentration [A] on the y-axis. Subfigure a depicts the tendency of the system to two stable equilibria (solid lines), the death state at [A] = 0 and the viable state (top curved line), an unstable equilibrium is depicted with a dashed line. Tendencies of [A] are depicted with vertical arrows, with a constant supply of [F] the system at point r moves to the stable living or viable equilibrium, while departing from s it evolves to [A] = 0 and dies. Subfigure b displays a partition of the state space into Viable, Precious and Terminal regions derived from the tendencies of [A]. Subfigure c depicts the normative field as the positive change of [F] that is necessary at each point of the precarious region to avoid death. Subfigure d represents 4 different types of trajectories within the viability space: functioning or functional increase of [F] positively correlated with the normative field, malfunctioning modulation of [F] that is not correlated with the normative field and will eventually lead to death, non-functioning trajectories also lead to death by inactivity and subfunctioning trajectories are positively correlated with the normative field (pushing [F] to increase) but fail to save the life of the organism (see text for more details).

This classification captures biological nuance that the dual-order model cannot, such as partial failures within a single regime or regulatory dysfunctions at higher systemic levels.

What I offer is a more parsimonious, gradated, and inclusive framework. Rather than splitting the world into constitutive and regulatory norms, my approach captures both under a unified formalism. Biological systems, after all, are full of gradual regulation, not binary switches. Hormones, enzyme levels, and neuronal excitations rarely flip like light switches—they modulate, fine-tune, oscillate. In short, I argue, the Normative Field Approach provides a robust and flexible model for understanding malfunction.

I conclude with a short metaphysical exhort on the nature of functions that I feel tempted to turn into a full paper: “From an operational perspective, norms appear as conditions of possibility for the organism’s very existence—within an extended present (or across scales of extended presents) that sustain the organization anchoring those norms. This does not exactly render norms epiphenomenal; rather, it suggests an explanation that cuts across both epi- and sub-phenomenal levels. Normativity could be said to be epiphenomenal in the sense that it offers a higher-order normative description of system operations—descriptions that different parts of the system may or may not conform to, to varying degrees. At the same time, it is sub-phenomenal (and thus transcendental in the Kantian sense) insofar as it refers to modes of functioning among parts that constitute the very conditions of possibility for the system’s ongoing existence. For the system to exist as an observable entity here and now, the normative description must already have been satisfied.” (p. 16)

«it suggests an explanation that cuts across both epi- and sub-phenomenal levels.» (p.16)

This way of conceiving (mal)functions has consequences. Particularly if we are to avoid normalizing instrumentations of functionality and dysfunctionality (e.g. by claiming that somebody’s behaviour is dysfuctional because it deviates from statistical normality or from historical competitive selection) and favours instead a system centered, environmentally sensitive, open and singular account of function anchored on the autonomy of the system under care:

“[I]t is ultimately the autonomy of each living organization (in its open and interdependent singularity and becoming) that marks the horizon of normative judgements.” (p.16)

Here is the full paper:

Barandiaran, X. E. (2025). Organizational Accounts of Malfunction: The Dual-Order Approach and the Normative Field Alternative. Biological Theory. https://doi.org/10.1007/s13752-025-00500-z

ABSTRACT: The notion of malfunction is critical to biological explanation. It provides a test bed for the normative character of functional attribution. Theories of biological functioning must permit traits to operate but, at the same time, be judged as malfunctioning (in some naturalized, nonarbitrary sense). Whereas malfunctioning has attracted the most attention and discussion in evolutionary etiological approaches, in systemic and organizational theories it has been less discussed. The most influential of the organizational approaches (by Saborido, Moreno, and Mossio) takes a dual-order approach to malfunctions, as a set of functions that fit first-order constitutive norms but fail to obey second-order regulatory ones. We argue that this conception is unnecessarily complicated (malfunctions do not need to arise as a result of two conflicting orders of norms) and too narrow (it excludes canonical cases of malfunctioning). We provide an alternative organizational account grounded on viability theory. The dynamics of the traits that constitute an organism define the normative field of its viability space: sugar must be replaced at a certain rate, blood must be pumped at a certain pace, and so on. A trait operates normatively when its effects on the viability space correlate positively with the normative field. Three senses of dysfunctionality might be distinguished: subfunctional operations are those that positively correlate with the normative field but quantitatively fail to match the required speed; malfunctional operations are those that do not positively correlate with the normative field; and nonfunctional traits either don’t operate at all or operate with null effect on the normative field.