Major Problems and Subfields

Major problems and sub-fields

Composition and Parts

Principle of Compositionality

Much about composition of sentences is addressed in the work of linguistics 
of syntax.

The philosophy of language has one core contribution, which is the principle 
of compositionality. It states that the meaning of a complex expression is 
completely determined by the meaning of its parts and their structure.

While simple sounding, it allows the philosopher of language to infer 
something that may be quite helpful. The principle of compositionality states 
that in a meaningful sentence, if the lexical parts are taken out of the 
sentence, what remains will be the rules of composition. Take, for example, 
the sentence "Socrates was a man". Once the meaningful lexical items are 
taken away - "Socrates" and "man" - what is left is the pseudo-sentence, 
"S was a M". The task becomes a matter of describing what the connection 
is between S and M.


Problem of universals and Composition

One debate that has captured the interest of many philosophers is the debate 
over the meaning of universals. For example, when people say the word, 
"rocks", what do they mean? Does the expression stand for some real entity 
out there -- or is it, rather, a collection of particulars that are just 
referred to be some name? The former position has been called philosophical 
realism, and the latter has been called nominalism.

From the radical realist's perspective, the connection between S and M is a 
connection between two abstract entities. There is an entity, "man", and 
an entity, "Socrates". These two things connect together in some way or 
overlap one another. Plato's theory of forms was like this.

From a nominalist's perspective, the connection between S and M is the 
connection between a particular entity (Socrates) and a vast collection 
of particular things (men). To say that Socrates is a man is to say that 
Socrates is a part of the class of "men".

Another perspective is to consider "man" to be a property of the entity, 
"Socrates". A property is a characteristic of the thing.

Still another perspective considers "man" to be the product of a propositional 
function. A propositional function is an operation of language that takes 
an entity (Socrates) and outputs a proposition. In other words, a 
propositional function is like an algorithm. The meaning of man is 
whatever takes the entity, "Socrates", and turns it into the 
statement, "Socrates is a man".


Meaning

The answer to the question, "What is the meaning of meaning?", is not 
immediately obvious. One section of philosophy of language tries to 
answer this very question.


Ideas and Meaning

The classical empiricists are usually taken to be the most strident 
defenders of the idea theory of meaning.

David Hume is well-known for his belief that thoughts were kinds of imaginable 
entities. (See his Enquiry Concerning Human Understanding, section 2). It can 
be inferred that this perspective also applied to his theory of meaning.

His forebearer, Locke, seemed a bit more skeptical, considering all ideas to 
be both imaginable objects of sensation and the very unimaginable objects of 
reflection. These perspectives, too, may be used to infer a parallel theory 
of meaning.

Mental images, sounds, and recollections have been called "mental 
representations" in current literature.

Over the past century, the idea theory of meaning has been criticized by 
many philosophers for many reasons.

One criticism is that ideas are unable to account for the different variations 
within a certain meaning or type. For example, any hypothetical image of 
the meaning of "dog" has to include such varied images as a chihuahua, a 
pug, and a Black Lab; and this seems impossible to imagine. Another way 
to see this point was given by Ludwig Wittgenstein, who argued that if we 
have an image of a specific type of dog, why should it represent the 
entire concept, including breeds that look very different?

Another criticism is that some meaningful words, known as non-lexical 
items, don't have any meaningfully associated image. For example, the 
word "the" has a meaning, but one would be hard-pressed to find a mental 
representation that fits it.

Another is a problem of composition - that it is difficult to explain how 
words and phrases combine into sentences if only ideas were involved in 
meaning.

But the idea theory of meaning has lately been defended in new form. 
Called the theory of prototypes, it suggests that classes are formed on 
the basis of ideas of a particular, ideal token. For example, the category 
of "birds" may have the idea of a robin as a prototype, and then the 
limits of the meaning of bird (for example, a penguin) are sorted out 
through further experience and observation of like characteristics between 
robins and other similar animals. This theory has been defended by contemporary 
cognitive scientists Eleanor Rosch and George Lakoff.


Truth and Meaning

Some have asserted that meaning is nothing substantially more or less than the 
truth-values that they reveal.


Frege, Russell, and Reference

Classical logicians had known since Aristotle how to codify certain common 
patterns of reasoning. For example, the argument "Socrates is a man; All men 
are mortal; Therefore Socrates is mortal" is called a syllogism. This can also 
be called a valid syllogism, because if its premises are true, its conclusion 
must also be true. It can be represented like this: "All A are B. All B are 
C. Therefore all A are C."

But the turn (or, perhaps, Renaissance) of language philosophy is tied 
closely to the development of modern logic. It began with the work of the 
German logician Frege in the late nineteenth century. Frege, simultaneously 
with Boole and Charles Sanders Peirce, advanced logic significantly by showing 
how to codify inferences using Sentential connectives, like and, or and 
if-then, and quantifiers like all and some. Much of this work was made 
possible by the development of set theory. Frege was a philosopher of 
mathematics, who loathed appealing to psychologistic or "mental" 
explanations for meanings. His original purpose was very far from questions 
about meaning -- he wanted to use modern logic to further develop the 
foundations of arithmetic. He first undertook to answer the question, "what 
is a number?" or "what objects do number-words ("one", "two", etc.) refer 
to?" But in pursuing these matters, he was eventually confronted with the 
task of analysing and explaining what meaning is.