The conventional material ontological view of the biosphere, discussed in the previous article of the series, projects living beings as a composite of smaller constituents, divisible down to the level of atoms. This view, however, is insufficient to explain the dynamicity and diversity that is inherent, even essential to and immediately apparent in the living world. A fundamental re-imagination of the nature of the living world comes from the metaphysicians of biology who would like to look at the biosphere as a collection of processes, not materials. The development of this processual view is the focus of this article. 

Like the materialist worldview, the process description of the natural world has its historical trajectory within the Grecian schools of philosophy. Within classical Grecian philosophy, processual thought can be traced back to Heraclitus (around 530 BCE — 470 BCE)[1]. Heraclitus belonged to a group of early philosophers termed monists who believed in a singular aspect (the arche) that fundamentally constructs the natural world. The reader may be familiar with some aspects of monist thought, even if one is unfamiliar with the term – for instance, some of the monists’ arche included the infamous Grecian elements – earth, wind, water and ether. 

For Heraclitus, the arche principle was fire, which emphasized flux or change; ​“Panta Rhei” or everything flows is what he was supposed to have held. Heraclitus is most famous for a saying that is often attributed to him,​“you cannot step into the same river twice.” Here he alludes to the ever-changing and dynamic ontology of both the river and the temporally individualized being who steps into it. In other words, both the river and the person are forever becoming.

A contemporary philosopher of biology who is attempting to champion the processual ontology of the living world is John Dupré with the University of Exeter. In a book he co-authors with Daniel Nicholson titled ​“Everything Flows – towards a processual philosophy of biology”, Dupre offers a framework to discuss the processual nature of biological entities. Here, 

1. Processes are considered more fundamental than substances. A substance is but a temporal abstraction of a process. Processes yield materialities that are then amenable to sensory engagement in their temporally stabilized form; making the latter dependent on the former. We are conditioned intuitively to imagine processes as something that is carried out by materials. This is a view that processual ontologists aim to correct. For instance, we are intuitively inclined to think and speak of ​‘Enzyme catalysis’ as a process that happens due to the structural and compositional properties of a protein called the Enzyme. However, a processualist might argue that an enzyme itself exists as a consequence of the process of protein synthesis before being broken down by the process of protein degradation. Several other processes, occurring at various other spans of time have to co-occur in the duration that the enzyme is available for catalysis, for catalysis to happen (this is also elaborated in point 3.). 
2. Processes have temporal parts, unlike substances which have spatially measurable parts. Time rather than space is a more useful measure to describe a process. 
3. Lastly, processes are relational. Simply put, they too exist in hierarchies or nestations where one process influences and informs another.

Let me illustrate this with an example from one of the most fundamental processes that qualify living organisms – metabolism. This is something exclusively alluded to in Dupre and Nicholson’s book. Conventionally, metabolic reactions are imagined as nothing but mass-energy transitions that obey the laws of thermodynamics. Here, a metabolite in metabolic reactions is considered the agency for these transitions. These transitions are regulated crucially by a class of molecules called enzymes. Living organisms are considered to be open systems, continuously exchanging matter and energy with their surrounding environment. However, living organisms exist in an imperfect equilibrium, where some of the matter consumed is utilized in the construction of its own infrastructure and the energy consumed is utilised in both this constructive mechanism and towards performing crucial biogenic functions, chief among them being replication. In order to maintain this imperfect equilibrium, the living organism must constantly consume and constantly work at these matter-energy transitions. 

Unlike machines that operate within the laws of thermodynamics and whose structural integrity is independent of the fuel they consume, living organisms must constantly act, and engage in constant change to maintain their integrity. Within each organism, each metabolite only comes into existence as a consequence of a reaction and is almost immediately used as a substrate for further such reactions until it can no longer be transitioned and is eliminated from the organism. In other words, a metabolite is available only for a small fraction of time and as is often the case, may act as a precursor or intermediary in more than one metabolic pathway. 

The enzymes that catalyse these reactions, themselves have temporally stabilized windows of existence, preceding which they are synthesized from genetic information and broken down by proteolysis, the products of this proteolysis utilized for further rounds of protein synthesis. In the nested framework posited by Dupre and Nicholson, within a larger temporal framework, each enzyme is subject to its own evolutionary trajectory and the enzymes that are available today are only extant versions of an ongoing process. 

Each cell that we encounter, within which these metabolic processes are compartmentalized, remember, is also confined to its own differentiation, developmental and evolutionary timelines before coming into existence and eventually being subjected to a tightly regulated deconstruction process called apoptosis. Each organism within which the cell is in turn found, is itself operating as an extant individual with developmental and evolutionary timelines. And subsequently, the biosphere is a composite of symbiogenically existing processes with their respective timeframes of operation. 

This in a nutshell is the processual ontology of the living world.

‘What is the living world made of?’, Now that we reflect upon this question, we realize that depending on how one chooses to study the components of the biosphere, it is critical to be aware of the nature of being of each component investigated. It may be safe to assume that the distinct perspectives discussed in the two articles could be combined to provide a better understanding of the living world than either one of them alone. This assumption may, to borrow a line from Dupre and Nicholson’s work, ​“have interesting and sometimes unexpected consequences on fields as diverse as physiology, genetics, evolution and medicine, where it forces us to question deeply ingrained assumptions and revise basic theoretical tenets.”