Table 1.
The theoretical virtues, as classified by Keas (2018), and their pragmatic/problem-centric construal
| Evidential virtues |
About how well theoretical components correspond to events and regularities in the world, Pragmatic construal: heuristics for a theory’s problem coverage based on the relationship between the theory and phenomena, |
|
| Definition (Keas et al., 2018) | Pragmatic construal | |
| Evidential accuracy | A theory (T) fits the empirical evidence well (regardless of causal claims) | Ability to cover problems that require empirical accuracy to a certain degree about specific observed phenomena |
| Causal adequacy | T’s causal factors plausibly produce the effects (evidence) in need of explanation | Ability to solve problems about the originally observed phenomena that require manipulation or prediction with extrapolation to unseen circumstances |
| Explanatory depth | T excels in causal history depth or in other depth measures such as the range of counterfactual questions that its law-like generalizations answer regarding the item being explained | Ability to be applied to problems involving other, related phenomena |
| Coherential virtues |
Pertain to how well theoretical components fit together Pragmatic construal: heuristics for a theory’s problem coverage based on internal structure and relationship to other theories |
|
| Definition (Keas et al., 2018) | Pragmatic construal | |
| Internal consistency | T’s components are not contradictory | Without—may give conflicting solutions. Unable to get a clear answer from the theory itself |
| Internal coherence | T’s components are coordinated into an intuitively plausible whole; T lacks ad hoc hypotheses—theoretical components merely tacked on to solve isolated problems | Suggests T will be able to be readily applied to other problems without further problem-specific modification |
| Universal coherence | T sits well with (or is not obviously contrary to) other warranted beliefs (e.g., other theories) | Without—conflicting solutions with other theories: which theory to choose? |
| Aesthetic virtues |
Possess an aesthetic shape (fittingness) that is qualitatively different from the logical-conceptual fit of the coherential virtues Pragmatic construal: subsumed by agential virtues, based on the relationship between the theory and various agents |
|
| Definition (Keas et al., 2018) | Pragmatic construal | |
| Beauty | T evokes aesthetic pleasure in properly functioning and sufficiently informed persons | A theory aligns with the aesthetic preferences of theory-using agents (agent appropriateness) |
| Simplicity | T explains the same facts as rivals but with less theoretical content | A theory plays to the usability and understandability constraints of theory-using agents (agent appropriateness) |
| Unification | T explains more kinds of facts than rivals with the same amount of theoretical content | - > Communal facilitation |
| Diachronic virtues | Can only be instantiated as a theory is cultivated after its origin | |
| Definition (Keas et al., 2018) | Pragmatic construal | |
| Durability | T has survived testing by successful prediction or plausible accommodation of new data | Examples of a theory’s problem-solving accomplishments |
| Fruitfulness | T has generated an additional discovery by means such as successful novel prediction | |
| Applicability | T has guided strategic action or control, such as in science-based technology | |