The Language of Theories Linking science directly to ‘meanings’

Meaning and existence One central topic of the day was how scientific theories come to be applied to the world– how they are related to observations & pragmatic interaction with the world. Another topic was whether we should regard theoretical entities as real things, or as mere convenient ‘posits’ that are adopted to help us organize/ systematize facts about observations that can be expressed without using theoretical language.

Postulated entities These are unobserved (in some sense). Postulating them is part of what we do when we adopt certain kinds of theory. Empiricism seems to suggest that anything unobserved is inessential– we don’t need to really believe in these things for their postulation to be useful. After all (say the positivists) we don’t want science to become another route to (bad old) metaphysics, full of postulations that ‘explain’ things using a purely speculative framework that doesn’t really advance our understanding.

The picture (again) Theory: An uninterpreted calculus. We have rules of inference, various predicates & etc. here, but it’s all set out without regard to application. Obs: The observational framework– a language in which we can report various features/aspects of what’s going on around us. (This can be theoretical from another point of view, but S. accepts a truly non-theoretical level that Carnap called ‘physical-thing language’.) Correspondence rules: Link Obs to theory, so that, on making certain observations, we can infer some claim(s) in the theory, and on reaching certain theoretical results, we can infer some claims about observations.

The job of a theory To capture inductively confirmable generalizations in the physical thing language, by deriving them via the correspondence rules and the theory. Correspondence rules are sometimes construed as partial definitions (partial interpretations), but Sellars rejects this, especially for theories that include unobserved micro-entities. For Sellars the key point about these rules is that they allow inferences in both directions, from obs to theory and theory to obs.

Meanings Section II explores a wide range of ideas and remarks about meaning (which is a complex, multi-faceted thing). So we have: –Meaning as translation. –Meaning as sense. –Meaning as naming. –Meaning as connotation. –Meaning as denotation.

The aim here Sellars wants to establish and reinforce the distinctions between these and to give the reader a clearly sense of how they fit together. Translation requires what is translated and its translation to have the same use (in some sense of use). Hence we should say, in this sense, “‘round’ means circular,” rather than “‘round’ means circularity.”

More meanings Means as ‘expresses the concept’. Here we do get, ‘round’ means circularity (i.e. ‘round’ expresses the concept circularity). Nearby is: ‘Roundness’ names the concept circularity. One word’s meanings take many different forms: ‘Parigi’ means (translates) Paris; ‘Parigi’ names Paris; ‘Parigi’ expresses the concept Pariseity (=being Paris). Connotation comes in via inference: ‘Parigi’ connotes the property of being the capital of France. Finally, denotation has to do with what we commonly call extensions: ‘Red’ denotes red things.

Theoretical language In many senses of meaning, there is no problem in saying that theoretical terms have meaning. –‘Molekul’ (in German) means (translates) molecule. But this assumes we have ‘molecule’ in our current, useful vocabulary, that is, that we know how to use it. If it’s just a ‘marker’ in an abstract, unapplied theory this is pretty thin gruel.

Linking different senses of meaning Translation and concept-expression: To say that ‘round’ expresses the concept circularity is really no more than to say that ‘round’ means circular in the translation sense. ‘Circularity’ is just a name for the linguistic role that ‘circular’ plays. In both cases, we are saying just that ‘round’ plays the same role (in English) as ‘circular’… Concepts are distinct from senses, which are more general (senses capture ‘roles in language use’ of any kind; concepts apply to roles of a more restricted sort which Sellars doesn’t explore here). At this point theoretical words can, by our lights, express concepts (since that really just comes down to translation meaning, and they do have that, at least).

Pressing the question But do they name anything? Do they denote anything? These notions are often invoked as the key to making a word-world connection. To name something is for a word to pick out something in the world, something that exists; to denote is to apply (pick out) the elements of some collection of existing things.

Connotation, naming and denotations Connotations are the criteria by which we pick out the things (objects) named. Two types of thing: individuals (Socrates) and concepts (Roundness). Singular terms for concepts are formed from the words that are said to express those concepts– Roundness from round, circularity from circular, etc. Distributive singular terms (the pawn, the lion, etc.) abstract from the individual instances (pawns, lions) to provide a convenient way of capturing (expressing) generalizations (the rules for pawns in chess, the charateristics connoted by lion).

Entities Entities (real, individual things) are non-conceptual objects. Obviously a scientific realist wants to take the entities postulated by scientific theories seriously. We distinguish basic from derivative entities: Derivative entities can be eliminated by contextual definitions (translating any talk that seems to refer to them into talk that only includes names for basic entities). If a name names something that something satisfies the connotation of the name, and so satisfies the concept expressed by the name. The key case is common names (lion, electron, quark,…)

Substitutions Sellars takes quantification here (p 116) to be substitutional. That is, the range of cases covered by a quantified sentence that expresses ontological commitment to (say) electrons is what we get by substitution of names into the appropriate places in the open sentence we get by stripping off the quantifier. If we substitute some other sort of word (a predicate, for example) then we’re not going to get existential commitment (no objects here– meaning only in the translational sense). Bringing in concept names to get around this leads to linguistic objects, not metaphysical ones…the force of ‘S is wise’ is not distinct from ‘S exemplifies wisdom’

Ramsey sentences Sellars: These are not existence sentences, despite the use of existential quantifiers. They quantify over predicate places, so there are no objects (beyond linguistic ones) referred to here.

The existence of molecules To know there are molecules, given all this, is to know that:  x:  1 x and  2 x and  3 x… Where meeting these conditions is sufficient for being a molecule. This sentence is a statement in the theory; so how do we know it? Correspondence rules let us infer such sentences from observations. So all we need to know this is to be entitled to the necessary observation claims and to be entitled to use the correspondence rules to infer these sentences. But the second entitlement comes easy: The theory must be a good theory. Do we have good reason to adopt the framework of molecules?