A review of Matteo Morganti’s From Ontic Structural Realism to Metaphysical Coherentism (2018)
Structural realism is a stance in the philosophy of science that has been topical since the 90s. This stance has two partitions, namely epistemic structural realism and ontic structural realism (OSR). Epistemic structural realism departs from the problem of theory shift in the history of sciences. Theory shifts in the history of sciences have shown that unobservable entities postulated by scientific theories are not truthfully there. Theory shift in sciences then presupposes different entities in scientific practices concerning unobservable reality. Based on John Worrall’s epistemic structural realism analysis on light theory, it is the mathematical structure that persists. This is for which per epistemic structural realism, only the structure of unobservable reality can be known. James Ladyman (1988) proposed a new interpretation of structural realism with different motivations. This interpretation departs from the metaphysical underdetermination of quantum physics and results in OSR.
Metaphysical underdetermination is different from underdetermination theory by evidence in theory choice. Based on Leibniz’s indiscernibility thesis, , the metaphysical status of unobservable entities, namely individuality, notably quantum particle, cannot be determined. In classical physics, this metaphysical underdetermination may not take effects. For example, suppose there are two particle objects, a, b, and two boxes. There will be four possible states, namely [ab] and [ ]; [ ] and [ab]; [a] and [b]; [b] and [a]. By assuming that each state is equally probable, the probability of each state is ¼. However, in quantum physics, the situation is different. Suppose there are two quantum particles and two boxes; so, the possible states are as follows: [xx] and [ ]; [ ] and [xx]; [x] and [x]; [x] and [x]. The third and fourth states are not different. Therefore, assuming that each state is equally probable, the probability is 1/3, meaning that the indiscernible principle of identity fails to be applied in quantum objects. As regards this result, Bas van Fraassen contended that metaphysical underdetermination results in a farewell to metaphysics because the metaphysical status of fundamental objects is indeterminate.
Ladyman shifted the focus of metaphysical categories from object to structure. With that, OSR is diverted from metaphysical underdetermination. However, instead of resolving the problem, OSR seems to desert the object altogether from fundamental metaphysical categories. This maneuver is similar to Erns Cassirer that fled noumena from the object of epistemological studies concerning reality. Nevertheless, OSR added additional move by reversing the order of ontological dependence from traditional metaphysics that is object-oriented to structure-oriented, in which structure is more fundamental than objects. With this reverse in the order of dependence, objects depend on structures. This maneuver alters the old conception of reality that supposedly fundamental reality is occupied by objects with intrinsic properties.
Matteo Morganti wards off the OSR maneuver by defending object in the metaphysical category as an ontological category on a par with structure. The relation of ontological dependence planned is mutual ontological dependence. In this framework, objects as a whole, coupled with their structures (systems of relation), make up reality. This metaphysical stance is called coherentism, which means that an object’s existence requires coherences with other objects without a hierarchy of reality. Coherentism here is similar to coherentism in epistemology.
In his article, at the outset, Morganti introduces structural realism and its variance. After that, he specifies its discussion on each OSR and how the continuity shapes OSR metaphysical views. The continuity takes place in how OSR claims the significance of symmetry and quantum entanglement in its ontology.
In the formal and general meaning, symmetry requires sameness (or equivalence) in some congruency with X, in its relation with changes (or transformation) in some congruency with X. Sameness in its association with changes lies on the determination of nature X, type of transformation determined, and at some point still the same to the transformation. The most familiar example is geometrical figures, special transformations (e.g., rotation), and figure sameness (e.g., congruency of shapes) in transformations. Consider the equilateral triangle; this triangle is symmetrical in its congruency on 120-degree rotation and its relation to a transformation that reflects or reverse the figure with its congruency on one of three symmetrical axes (figure 1).
Figure 1 Symmetric Triangle
An object that is more interesting than symmetry can involve other things, such as the law of nature (or its mathematical expression) that is capable of sustaining its content (or its form) under the transformation of the framework (or coordinate system). Nevertheless, symmetry, in general, is being hardened through mathematical terms of group theory. In this theory, symmetry can be defined as invariance under the transformation group. Group theoretical framework tightens intuitive notions of “sameness in its relations to changes” by showing how a symmetrical group partitions symmetry objects in equivalent classes. Its elements are related through symmetrical transformation.
The significance of fundamental physics is related to the symmetry of the standard model of particle physics (figure 2). This model includes electromagnetic, weak nuclear force (quantum electroweak), and strong nuclear force (quantum chromodynamics) and classify all elementary particles found. Discussion regarding the standard model can involve two features relevant to symmetry. The first is the Higgs mechanism, coupled with the Higgs field, which provides the mass obtained. The discovery of the Higgs boson lately, a quantum excitation of Higgs field, supports the standard model. The second is a certain symmetry, namely Poincaré global symmetry that combined all theories of relativistic quantum field and gauges symmetry SU(3) SU(2) U(1), which effectively defines the standard model and includes three fundamental interaction (nuclear, weak, and electromagnetic, respectively). The group SU(3) SU(2) U(1) can be said as a fundamental basis ontologically because it founds the standard model.
Figure 2 The standard model of particle physics
Another significance of fundamental physics is quantum entanglement. At least there are some composite quantum entanglements, which means, roughly, the components correlate to one another. For example, singular state
illuminates us that a system is composed of particles 1 and 2 such that the components necessarily produce spins with the inverse direction in the special direction given in measurement. Nevertheless, taken separately, 1 and 2, each individual has the same probability of spin upward and downward, which needs the same spin result for measurement (4).
The symmetry in the standard model and quantum mechanics, which its systems depend on OSR’s correlation, yields the metaphysics. OSR has metaphysical assumptions of the fundamental relational structure. Morganti classifies RSO into these three things (5):
- Strong OSR: only relational structure exists, and the object can be eliminated because objects are merely emergent entities or epiphenomenon.
- Moderate OSR: objects and relations lie on the same stage, as all properties are naturally relational. However, objects also exist as (nothing but) “placeholders” in the relevant structure.
- Contextualist OSR: some object properties may be monadic and structurally-irreducible. However, objects depend on the structure because fact about identity is always contextual, namely placed externally.
Based on the above classification, strong OSR is an eliminative metaphysics because only fundamental physical relations exist. At the same time, moderate and contextual OSR does not only allow objects to be eliminated but also grants fundamental status on objects and relations. Before entering to his analysis on coherentism, Morganti proposes three scenarios:
- Contemporary scientific feature, notably quantum physics, shows that relational structure is the ontological basis.
- The primacy of relational structure suggests that the relation of physical networks is more fundamental than objects, and objects should be eliminated (strong OSR) or made thin (moderate or contextual OSR)
- Strong, moderate, and contextual OSR does not necessarily recommend other ontological frameworks.
Morganti designs his enterprise to escape from OSR to coherentism from the three scenarios above. Morganti does not recommend that philosophy go back to scientific realism and object-oriented ontology that neglect quantum physics. Morganti still sees the significance of the continuity of the metaphysics of OSR with science as an excellent stepping point to establish naturalistic metaphysics. His approach is rejecting 2) and reinterpret 1). The notion that supports this strategy is different from what OSR assumes so far. The structural intimacy of contemporary science, especially quantum physics, does not necessarily stir us to ontological primacy of physical relations. It can be interpreted otherwise.
Morganti appropriates the doctrine of the objects depend on objects (ODO) and then contextualizes it in the context of mathematical structuralism as the basis to understand quantum physics. ODO can be formulated as follows:
(ODO) each object in D [where D is the domain of some mathematical structures] depends on every other object in D.
ODO is a holistic claim that refutes the general view that object is independent of each other. By contrast, ODO postulates’ global connectivity.’ In mathematics, the ODO principle can be seen as a kind of structuralism. However, in physics, if an object does not essentially depend on structure, it is another word of farewell to structuralism. For example, traditional objects and ipso facto intrinsic property can be reintroduced and granted ontological priority. However, Morganti claimed the inverse that ODO constituted a strong ground for the understanding fact of quantum physics. To introduce metaphysical coherentism, Morganti discusses two metaphysical views, namely foundationalism, and infinitism.
Foundationalism is one of the most prevalent metaphysical views. Foundationalism sees that the world has a vertical structure that is hierarchical and has a fundamental level (figure 3).
Figure 3 Inverse pyramid of foundationalism
Furthermore, pluralistic foundationalism is the most familiar one. Similar to foundationalism in epistemology, this view has multiple fundamental constituents, whether it is direct or not, all entities are not founded by other objects, that is independence. A familiar example is an atomistic view of the world. This view contends that basic entities with internal structure compose other higher-level entities, which in the case of OSR is structure. This foundationalism, at least, has four main theses:
Transitivity: if X depends on Y and Y depends on Z, so X depends on Z (anything that depends on anything dependent, it is dependent)
Antisymmetric: If X depends on Y, Y is not dependent on X (no entity that is dependent on each other)
Irreflexivity: X does not depend on X (there is any entity that is dependent on each other)
Fundamentality: in the end, everything depends on fundamentalia (the lower layer) in which the dependent chain ends
Foundationalism has also faced a challenge of infinitism. There is an infinite possibility of dependency and ontological priority (or ends with fundamentalia). This view can help OSR defended by Ladyman that there is no problem with relations without relata because relata can always be analyzed structurally. What is found in the lower level is another relation (structure), ad infinitum (figure 4).
Figure 4 Inverse pyramid of infinitism
Morganti proposed an alternative of these two metaphysical views, namely metaphysical coherentism. As a coherentist solution to the justification problem in epistemology, coherentism leave pyramid structure, antisymmetric, and last foundation. As Quinean web of belief, the reality that makes up the world relates mutually in a structure that is not established partially with cycle or rotation. Figure 5 may represent the schematic structure of coherentism.
Figure 5 The scheme of coherentism network
Coherentism rejects reflexivity because the cycle of priority and dependency relation finally get back to the first point. By re-questioning that metaphysical explanation should be based on reflexivity relation, coherentism can reject that this cycle necessitates reflexivity of relevant relation. Irreflexivity may be defended in a cycle by providing anti-transitivity (relevant relation cannot be transitive) or intransitivity (relevant relation is not always transitive). Furthermore, there is also quasi-transitivity that can catch a case in which, mutatis mutandis, a is prior to b, b is prior to c, but c is not prior to a because a is not identical to c. That is, the structure or sub-structure is dependent on each other except on itself.
Morganti provides an alternative for a metaphysical explanation of coherentism. That explanation is not trivial, such as ‘x is P because x is P,’ but ‘x is P; therefore Str is S, and x is R,’ in which x is a random physical object, P and R are two different properties from x, Str is a structure in which is in it and S is a property of Str. For example, a (type-)boson b is an essential element of ‘structure bosonic’ that determine (part of) the property b itself, in which b has a special independent situation, namely, intrinsic property that founds the bosonic structure. Furthermore, it determines the dependent-situation of b. The key factor of coherentism is played by all dependence relations in the mutual ontological network. With this, coherentism, which is inherently consistent and explanatory relevant to quantum physics, can be formulated (13-14).
Coherentism should be differentiated from relational holism, especially defended by Teller. Coherentism is similar to holism in terms of quantum entanglement that there is an irreducible relation on individual entities. However, coherentism makes a more general claim and not only to quantum entanglement. In addition, coherentism explicitly claims that everything is relational, that physical objects ‘exist simultaneously’ in ontological dependence, and not in the physical relations, namely concrete objects. Coherentism rejects that physical relation is prior to objects, or at least as fundamental as objects. By departing from the ODO assumption that affirms that object is also fundamental, and not derived from ‘up’ or ‘bottom,’ which for foundationalism believed as a more fundamental stage. For metaphysical coherentism, object and structure lie in the same horizontal level. The structure and object make up a structure of mutual dependence relations with other objects.
So, what should be done by OSR? Morganti gives two choices: 1) OSR should be understood as metaphysical coherentism, in which the intrinsic property and/or object or the identity of objects is determined by a holistic structure of coherentist type: or ii) OSR should be replaced outright with metaphysical coherentism in which the property or intrinsic identity is not determined relationally, but at the same time object cannot be autonomous in terms of existence, essence, or identity. Surely, Morganti prefers the latter.
Regarding the continuity between metaphysics and science, coherentism is as robust as OSR. Quantum entanglement can be understood as two individual objects interacted to create mutual ontological relation in proportion to relational properties appear. For types of particles and notions, properties, and particles determined by the relevant group characteristics can be interpreted in the holistic structure of mutual dependence with coherentist type. The structure exclusively involves physical objects and symmetric relation of dependence among them.
 Steven French dan Juha Saatsi, “Symmetries and Explanatory Dependencies in Physics” in Alexander Reutinger and Juha Saatsi (ed.), Explanation Beyond Causation, (Oxford: Oxford University Press, 2018), 186-187.
 P. J. Olver, Equivalence, Invariants, and Symmetry, (Cambridge, New York: Cambridge University Press, 1995).
 Steven French, “Toying with the Toolbox: How Metaphysics Can Still Make a Contribution” in Journal for General Philosophy of Science 49 (2), (2018), 211-230.
 Lih. Matteo Morganti, “The Structure of Physical Reality” dalam Ricki Bliss dan Graham Priest, Reality and Its Structure”, (Oxford: Oxford University Press, 2018), 258.
 Ricki Bliss dan Graham Priest, “The Geography of Fundamentality: An Overview” in Ricki Bliss dan Graham Priest, Reality and Its Structure”, (Oxford: Oxford University Press, 2018), 7. compare with Gabriel Oak Rabin, “Grounding Orthodoxy and the Layered Conception” in Ricki Bliss dan Graham Priest, Reality and Its Structure”, (Oxford: Oxford University Press, 2018), 38.
 Matteo Morganti, Op.Cit., h 259.
 P. Teller, “Relational Holism and Quantum Mechanics” in British Journal for Philosophy of Science Vol. 37, (1986), 71-81.