Chapter 4 marks a change in focus for Chakravartty’s project. In Part II, he begins looking at “more detailed illustrations of putative exercises in scientific ontology” (C, 99). However, Chakravartty stays away from explicit scientific content, instead deciding to focus on implicit scientific content, as it has been discussed far less and provides better examples of morals for scientific ontology (C, 100). In the supplementary reading, Amanda Bryant seeks an epistemological framework for a scientific metaphysics. In order to do so, she attempts to define a principle that prefers the simpler of two scientific theories. Bryant uses Okham’s razor as a mechanism to prove that a well-constrained, robust theory, is epistemologically preferable to a permissive, less-robust theory (this will be discussed in greater detail later).
The main thrust of Chakravartty’s argument in this chapter centers around the subject of dispositions. He starts out with an examination of dispositional properties, defining a disposition as “the ancient idea of a causal power,” and “a property that causes something to behave in a certain way” (C, 100). These properties contrast with categorical properties. A categorical property is static by nature. For example, the length of an object is always the same. Dispositional properties, however, can differ by circumstance. For example, the fragility of an object can differ depending on its surrounding environment. Bryant implicitly touches on this in her paper, as she discusses permissive and constrained theories. She posits that constrained theories are more likely to be true. Proponents of empiricism, and therefore constrained theories, are more agreeable to categorical properties, while dispositional realists (scientific metaphysicians) tend to side more with dispositional properties, which lend themselves to more permissive theories, or at least it appears that way on the surface. This will be discussed more later.
Dispositions used to be a fixture of philosophy, but fell on hard times during the early modern era. This might have been a result of the early modern’s tendency to split away from science (thanks for the history lesson, Professor). This ideological split makes sense, as dispositions allow for explanations of phenomena that would otherwise go unexplained. Scientists may ask why a certain entity behaves in “x” way. A dispositional realist would answer that the entity in question is disposed to behave that way (C, 101). Empiricists reject this view. Instead, they would say that there is nothing to explain past those phenomena simply existing. Although Chakravartty finds dispositions compelling, he does not believe that dispositional properties prove the existence of dispositions.
Chakravartty posits that dispositions can provide common ground for opposed aspects of scientific realism: entity and structural realism. Without dispositional realism, they are incompatible viewpoints. Dispositions are agreeable with entity realism because properties can be considered dispositions. Entity realists find these to be important, as they prove the existence of certain entities (C, 107). Regarding structural realism, dispositions can also serve as relations, as dispositions dictate how the manner in which the environment is supposed to behave. Dispositional realism reconciles the two opposing viewpoints, while also unifying our concepts of entities and properties with the causal process (C, 110). Chakravartty further drives this point home, positing that scientific laws are usually just relations between properties. This fact also does work for the dispositional realist, as properties are unified with all kinds. Chakravartty finishes this section by stating that, by finding dispositional realism attractive, one must in some way agree with scientific realism. However, as he recognizes, due to the metaphysical inferences, most people who agree with this position were already in his camp, or as he said, he is “preaching to the converted.”
One might think that there is a philosophical stalemate between dispositional properties and its deflationary analyses. However, there are new, transcendental arguments for dispositions.
P1: Objectionable claim regarding scientific practice
P2: The giving of relevant explanations presupposes Q (the reality of dispositional properties)
C: Dispositional realism
Chakravartty then moves to discussing the two main arguments that concern explanatory practice. The first argument comes in two flavors, dispositional regress and dispositional exercise. The second argument is the argument from abstraction.
Chakravartty starts with the dispositional regress and exercise arguments. For regress, Chakravartty starts by stating that dispositional concepts explain the behavior of entities. Basically, what he says is that as scientists discover more, which should dispel the need for dispositions, there will always be new, finer grained issues that cause the need for even more dispositions (C, 113).
He then goes through the disposition exercise argument. This argument centers on the fact that sometimes dispositional properties are acting, or “triggered,” without the actual manifestation of a certain behavior. Chakravartty uses an example from Nancy Cartwright, describing two negatively charged particles that are exactly balanced. Despite the undeniable forces at play, the particles do not move. Without an appeal to dispositional realism, there is no explanation for this event. This argument makes a case for dispositional realism, as dispositions can exercise without manifesting, which is something that categorical properties cannot do. It is important to mention that these exact situations (which are inherently inexplicable without dispositions) prove that Bryant’s epistemological framework for scientific metaphysics are more apt for justification, and not discovery.
Lastly, Chakravartty goes through the argument for abstraction. Transcendental in nature, it is focused on the efficacy of scientific methodology in case of abstraction (C, 117). Basically, he argues that abstractions could not be used, if not for the fact that they reveal information about dispositions. As an example, Chakravartty uses the application of laws from one closed system being transferred into another, non-isolated system. Closed conditions abstract from naturally occurring phenomena in this world, and laws only describe isolated systems. However, scientists regularly apply this knowledge to non-isolated systems. Chakravartty argues that laws should be interpreted as describing dispositions, saying “such dispositions often play a role in more complex situations, even if the precise manifestations they produce in isolation are mitigated or altered when combined with other dispositions” (C, 118-9). However, there are no guarantees about successfully exporting knowledge into more complex systems. Due to the lack of this guarantee, Chakravartty posits that abstraction provides no argument for the reality of dispositions (C, 120). Dispositions could just be the result of circumstance interacting with categorical properties.
Consolidating Scientific Knowledge
Chakravartty then moves towards the explanation of his argument. He allows that the conclusions of his prior efforts to explain science result in conflicting judgements, in which incompatible models incorporate incompatible assumptions. However, he believes that dispositions can rectify this problem. Chakravartty acknowledges the fact that models and theories often end up producing inconsistent descriptions (C, 121). However, being able to resolve these different descriptions into a unified picture would be good in the pursuit of knowledge. He uses water as an example. Water is a continuous, incompressible medium. It is also a collection of discrete particles. However, an entity cannot be both a continuous medium and a collection of discrete particles.
Incompatibility, to the dispositional realist, could just be a description of the different dispositions. Rather than attempting to describe what a fluid is, Chakravartty believes that dispositional realism could allow us to know what a fluid does. In other words, dispositions allow us to look at the behavior of an entity instead of its nature. This is where Bryant’s thesis is applicable; by constraining their hypotheses, scientists can increase the likelihood that those hypotheses are correct, which, in turn, makes them epistemologically preferable. The resulting concern is that dispositional realists have strayed from the pursuit of science — science is supposed to be about discovering and justifying the nature of entities (C, 124). Through an empiricist lens, that pursuit would be achieved by understanding the properties of an entity. However, it is important to remember that for dispositional realists, properties are dispositions. Chakravartty says it better:
“Thus, a description of the dispositions of something to behave in the ways it does, under the kinds of circumstances that elicit those manifestations, is unavoidably part of the description of the nature of the thing” (C, 124).
So what does dispositional realism do? According to Chakravartty, it’s a placeholder (C, 124). Saying what a thing does is much more flexible than what a thing is. So, although it is not as strong, dispositional realism does serve a purpose. Bryant agrees, saying that “it is better to have a descriptive and explanatory theory that is only somewhat likely than to have a theory that is not particularly descriptive or explanatory, but a good deal likelier” (B, 12). Until scientists can truly discover the nature of things, dispositions give them something to work with. By not making a genuine ontological commitment, the dispositional realist helps themselves. Furthermore, as Chakravartty posits, discussing the relevant dispositions of a thing is to describe the ontology of said thing (C, 126). He knows that this does not settle the perennial debate, but thinks that this is a step in the right direction.
Chakravartty then confronts the issue of what makes a given property the property that it is, as opposed to another. His answer: the dispositions. Empiricists say that properties are “quiddities,” which basically posit that the nature of the property itself is unknowable (C, 129). Bryant agrees with this evaluation, which is why she sides with Chakravartty in promoting scientific metaphysics. Nothing can be said about a given property other than it is different than other properties. This is the big logical conflict with the empiricist ideology that Chakravartty wants to point out: the philosophy that holds itself as the best method of observation, but also holds that it cannot describe the differences it discovers. Chakravartty allows that science cannot answer everything. Metaphysics will still have some role to play. Bryant buttresses Chakravartty’s opinion, saying “we should tie metaphysics to science because the road to knowledge is empirical, and because science seems to be a paragon of empirical investigation” (B, 2).