Problems with sense--
****Try to recapitulate Locke discussion in terms of just sense.****
Our intuitive thought about why ``Smith believes that Mark Twain was happy,'' can be true and ``Smith believes that Samuel Clemens is happy'' is false involved a fact about Smith, namely that Smith does not know that Samuel Clemens is the same as Mark Twain.
The Fregean substitution argument did not get us this far though. It just got us to the fact that ``Mark Twain'' must mean something different from ``Samuel Clemens'' in the two sentences. If we call these meanings the senses, and we try to explain the possibility of one sentence being true and the other false in terms of Smith's ignorance of Twain and Clemens identity, then we are tempted to identify the sense with something that is grasped by any speaker who can competently use the language.
One might ask oneself whether the sense of an expression should be thought of in this individualistic way. First, it is not at all clear to me that our intuitive thought about why ``Smith believes that Mark Twain was happy,'' can be true and ``Smith believes that Samuel Clemens is happy'' is false is correct. Isn't it possible that ``Smith believes that Mark Twain was happy,'' ``Smith believes that Mark Twain is Samuel Clemens,'' are both true, while ``Smith believes that Samuel Clemens is happy'' is false? Surely Smith could be illogical on this point. Probably all of us have inconsistent beliefs to some degree. The point is, it is not inconsistent for us to attribute inconsistent beliefs to Smith. Moreover, in many cases people do have inconsistent sets of beliefs.
This might causes some problems with the above theses. Thesis 10 and 17 and 8 were
Shouldn't it be a constraint on the way thesis 8 works that there are no inconsistent sets of sentences? That is, we would expect sense to be such that it was never the case that a given world can make "Mark Twain was happy," and "Mark Twain is identical to Samuel Clemens" both true, and "Samuel Clemens was happy" false.
So people can have inconsistent sets of beliefs, but sense should be such that no world can make an inconsistent set of sentences true (it should be in virtue of meaning that "Mark Twain was happy," and "Mark Twain is identical to Samuel Clemens" and "Samuel Clemens was not happy" can't all be true). In some weak sense at least then, sense has to be something transcending what is going on in someone's head, as whatever is going on in our head does allow inconsistent sets of sentences to be believed to be true. This might be taken as reasons to give up either thesis 10 or 17.
There may be other reasons for giving up on 10 or 17. Twin earth-- Person the same but senses of words different.
discuss descriptions and verification conditions and
try to figure out which theses should be chucked.
2 Problems about sense and analysis
3 Problems about indirect reference and belief contexts
4 Problems about bearerless names
5 Kripke's objections