Humphreys’ transformational emergence and its (difficult) reception

In his last book —his very own Philosophical papers (2019)— Paul Humphreys was adamantly clear about the way in which he finally came to believe that contemporary philosophical discussions about emergence were detrimentally prejudiced. According to him indeed, « synchronic approaches to emergence need to be abandoned if we are to successfully represent the full spectrum of emergent features in the world ». By « synchronic approaches to emergence », Humphreys was referring to the standard, Kim-style way of conceiving of emergence, encapsulating the following four necessary tenets (Humphreys 2021): (i) a commitment to some given hierarchy of so-called « levels »; (ii) some meaty ontological claim, typically associated with worldly features like « downward causation »; (iii) a commitment to the immutability of ontological posits (be they laws, properties or objects); and finally (iv) a frontal opposition of emergence with reduction. Such a strong claim, which many contemporary philosophers enamored with emergence are today considering as somehow heretical, actually was the upshot of a decades-long reflection about emergence, with a special emphasis on how the concept could finally come to have some scientific, and in particular physical, significance, over and above the typical toy examples and gratuitous claims of many metaphysicians or philosophers of mind. It is indeed from quantum physics that Paul Humphreys got his first inspiration to devise what has always been a powerful, influential —although already heterodox— account of emergence, notoriously referred to as « fusion emergence » (Humphreys 1997). This early proposal, as any « out of the box » idea in philosophy, triggered intense discussion, leading Humphreys to revise, sharpen and extend his ideas. After some detour towards the way in which emergence could be at play in computational science (Humphreys 2008), Humphreys’s reflection culminated in his account of transformational emergence, constituting the very backbone of his emergentist manifesto: Emergence. A Philosophical Account (2016), an account that opened the door for a wide range of new investigations today gathered into the umbrella category of « non-standard approaches to emergence » (Sartenaer & Baysan 2021). In the present chapter, we will follow three different objectives. First, we will expose the ways in which Paul Humphreys’s way of looking at emergence reframed the contemporary discussion about emergence and how it opened unsuspected new threads of fruitful investigations, in a context where debates framed under the synchronic, standard perspective were mostly stagnating. In particular, we will continue the (unfortunately) unfinished business of Humphreys consisting in elucidating the historical antecedents of his account of transformational emergence, and show how such an investigation could shed new lights on contemporary issues that plague emergentism. Second, we will offer some sort of sociological reflection as to why Humphreys’s take on emergence, though very fecund, has had a difficult reception in the —or actually rather some— community of philosophers. This will allow us to describe a dormant community conflict that unfortunately hinders the chance to move forwards, which is mostly typical of a bad articulation between metaphysics and (philosophy of) science. Finally, we will propose some ways of improving on or complementing Humphreys’s proposal, together with some new empirical case studies that might reinforce its plausibility. Indeed, a search of the scientific literature reveals numerous systems, not described using levels, that undergo radical transformations in their dynamics without being fully explained by the action of a law or a mechanism. Many of these cases have been overlooked by the philosophical community. In this chapter, we aim to explore three such examples, each of which makes the concept of transformational emergence more plausible: 1. Mass gatherings: According to researchers like Hopkins and Reicher (2016), participants in mass gatherings can experience profound transformations—cognitive, relational, and emotional. These seem strong enough to be understood as emergent properties. 2. Changes in biological modality: In biology, many typical regularities—those we might attribute a certain modal strength to—depend on historical events in the evolution of life. These regularities, often modeled as mechanisms, emerge at specific moments and may disappear over time. When they become constraints shaping the evolution of life, they can open up new possibilities for organisms, such as the emergence of life itself or evolutionary innovations that grant access to new ecological niches. These instances exemplify transformational emergence. 3. Topological quantum phase transitions: In recent decades, topological orders—a specific type of quantum order—have become one of the main areas of research in condensed matter physics. In such systems, a change of order signifies a transition that entails a profound shift in dynamics. For instance, in the fractional quantum Hall effect, the transition gives rise to the unexpected phenomenon of fractional statistics. As a result, the excitations in the quantum field of matter are neither bosonic nor fermionic, which would otherwise be considered impossible in 3+1 dimensions.