Theory (Barseghyan-2015) Reason1
It has often been argued that theories are best construed not as propositions but as models which are abstract set-theoretic entities. Importantly, on this model-theoretic or semantic view of theories, models do not contain propositions but are structures of non-linguistic elements.1 Whether this is indeed the case is to be established not in this metatheory but in an actual TSC (in collaboration with HSC). What is important from our perspective is that, even on this model-theoretic view, knowledge of the world depends crucially on formulating descriptive propositions.2 For something to become accepted as true or truthlike it must be expressible in descriptive propositions at least in principle. Often propositions are not explicitly formulated but are accepted tacitly. However, what matters is that in principle they too can be expressed as propositions. If something is not expressible as a proposition, then it cannot have a truth value and cannot be accepted or unaccepted as the best description of anything. Take an example of the Aristotelian-medieval model of the cosmos. When the medieval scientific community accepted this model, the community essentially accepted a tightly connected set of propositions, such as “the Earth is in the centre of the universe”, “the Moon, the Sun and all other planets are embedded in concentric crystalline spheres which revolve around the central Earth”, “all celestial bodies are made of element aether”, “aether is indestructible”, “aether has a natural tendency to revolve around the centre of the universe”, “all terrestrial bodies are made of the four terrestrial elements”, etc. In short, while models may as well play an important role in scientific practice, no part of these models can be actually accepted or rejected if it is not expressible in descriptive propositions. Thus, from the perspective of our project, it is safe to treat theories as collections of propositions.This reason for Theory (Barseghyan-2015) was formulated by Hakob Barseghyan in 2015.3
- Suppe, Frederick. (1989) The Semantic Conception of Theories and Scientific Realism. University of Illinois Press.
- Chakravartty, Anjan. (2007) A Metaphysics for Scientific Realism. Cambridge University Press.
- Barseghyan, Hakob. (2015) The Laws of Scientific Change. Springer.