General points of Gottlob Frege’s Sense and Reference
Gottlob Frege begins by asking what identity is. Is it that which refers to the essence of a thing? If so, how is it being referred? The statements a = b and a = a can both refer to the same object (both a and b referring to a red ball for instance), but have according to Frege different cognitive values. Two signs can be used to reference the same object, so at least in this way their basic function is the same. But then why do we see something being different in the utterances ‘water is water’ and ‘water is H20’?
For Frege, the difference between saying ‘water is water’ and ‘water is H20’ is in their sense, i.e. they’re mode of presentation and of being presented. Before moving on, it might be useful to have some terms:
Name, combination of words, combination of letters, image, etc.
Mode of presentation.
The thing being referred too.
In regards to an object, the thing we refer to for Frege does not actually have to exist. What we tend to do however is presuppose a referent. Whenever this be the moon or the aether which exists between stars and planets.
Frege isn’t interested in the truth of the proposition, but rather what we do when we utter it in particular ways. Similarly, while characters in fiction, such as Odysseus have a sense and sign, it is doubtful whenever they have a referent that had an objective and grounded existence. We can often substitute different sentences with different senses and signs without any harm being done to the truth.
For example, we can substitute ‘Copernicus believed that the planetary orbits are circles’ and ‘Copernicus believed that the apparent motion of the sun is produced by the real motion of the earth’ without there being any harm to the truth-value of the utterance.
However, Frege points out that the referent of a sentence may not always be the truth-value of a sentence. Though both the morning star and evening star have the same referent i.e. Venus, we would be wrong to say that we see the evening star in the morning, and the morning star in the afternoon. The truth here then, has nothing to do with Venus.
Frege argues that in regards to people, though we might use the name x to refer to a person, our sense in which we express and comprehend the sign is different. If I like x, I may think or portray a positive depiction of x when I speak of the person. If I dislike x, then I will do the opposite.
Similarly, sense differs from language to language. The sense of an object may for example, have gender connotations (either being feminine or masculine) in one language, but be gender neutral in another.
Sometimes the exact sense of a sentence cannot be established due to ambiguity. For example, ‘that’s cool’ could refer to the temperature of something, or to something being fashionable or attractive.