SOPhiA 2018

Salzburgiense Concilium Omnibus Philosophis Analyticis

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Programme - Talk

A Problem with Sense
(Philosophy of Language, English)

In this essay, we will examine Frege's notion of sense and find it to be inconsistent. On the one hand, it will be found to be an externalist notion: the sense of a term is not determined by the psychological state of the user. This result is found when we consider Frege's method of definition and apply it to Hilary Putnam's famous Twin Earth thought experiment. Frege claims that the sense of a term is given by application of an equivalence relation. For instance, ''The number of Fs'' is defined as ''The class of concepts that are equinumerous with the Fs''. Putnam uses a similar technique, arguing that when we say that something is water, we claim that it bears the relation same liquid as to the substance normally called ''water'' by members of our linguistic community. Since it is an empirical matter whether that relation in fact holds (whether what we are pointing at is really H2O), the meaning of ''water'' is not exhaustively determined by the user's psychological state. Putnam is thus an externalist about meaning. Parallel remarks apply to Frege's notion of sense, given his method of definition. Thus, sense is found to be an externalist concept.
On the other hand, it can also be shown that sense is an internalist notion, exhaustively determined by the user's psychological state. We find this when we look at Frege's solution to the problem of identity substitution within the scope of propositional attitudes. If John believes that Hesperus is bright and Hesperus is identical to Phosphorus, it does not follow that John believes that Phosphorus is bright; he may not know that Hesperus and Phosphorus are the same celestial body. Frege explains this by pointing out that the referents of ''Hesperus'' are different in each case. When it occurs in a propositional attitude, ''Hesperus'' refers not to a celestial body, but to the sense of ''Hesperus'' as it is usually used. But this only solves the problem if sense is taken to be internalist. If John's psychological state does not exhaustively determine the referent of ''Hesperus'' within the scope of his propositional attitudes, then cases can be constructed in which ''Hesperus'' can be substituted with ''Phosphorus'' (or ''the evening star'', etc.) without John knowing the two to be identical.
So sense, as Frege understands it, implies an inconsistent epistemology. His method of definition requires a term's sense to be determined by factors other than the subject's psychological state; his use of sense to solve the identity substitution problem requires the opposite.

Chair: Nadja-Mira Yolcu
Time: 10:00-10:30, 14 September 2018 (Friday)
Location: HS E.002

Thomas Mitchell 
(University of Oxford, UK)

I am currently studying for a BPhil at Oxford, though will hopefully have finished by the time of the conference. Previously, I was an undergraduate at the University of Birmingham, also studying philosophy. In due course, I hope to move on to doctoral work.
Although my current paper is in epistemology and philosophy of language, my main interests lie in moral theory. Occasionally, they even tell the truth.

Testability and Meaning deco