The most important and significant issue regarding meaning is: How do we understand the meaning of a proposition? In other words, what sorts of mechanism are involved for acquiring the meaning of a proposition? As we have stated in the previous presentations, the meaning of a proposition is inseparably related to its truth-value of what that proposition asserts. In this connection, Wittgenstein in his 'picture theory of meaning' viewed that 'meaning' and 'truth conditions' are so related with each other that one cannot imagine a proposition without its truth condition.
In our earlier discussion on the meaning of a proposition, we have argued that the idea of meaning essentially includes the idea of logical bivalence as its essential component. This is because if we know the meaning of a proposition then we know the situations or circumstances where the proposition will be judged as true or false. Hence, the relation between the meaning of a proposition and its truth-value appears to be identical in the sense of having a "tight-knit-association". In this regard, Wittgenstein emphatically expressed that there is no indeterminacy of sense of a proposition. All the propositions must have sense because sense is the logical and intrinsic property of a proposition. Further, he said that sense is the criterion through which we determine the reference. In his view, to know the sense of a proposition means to know the conditions where the sentence is to be applied and where it is not. In other words, we are able to know the conditions under which the proposition will be true and false. The view expressed here corresponds to logical positivist's verifiability theory of meaning. According to them, the sense of a proposition is the method of its verification1. It is the verifiability theory which determines the truth-value of a proposition. Further, logical positivists assert that though meaning of a proposition is determined by its constituent words and the grammatical rules yet in some cases these principles are not enough or sufficient to acquire the meaning of a proposition. For example, suppose a person says "His dog is very crazy", or "Motion is restless". In this case to understand the propositions it is not enough for us to know the meaning of its constituent words and the grammatical rules through which the proposition is governed, rather we should know the situations where the sentence is to be applied and where it is not. In other words, under which circumstances the proposition will be treated as true and under which circumstances the sentence will be treated as false. Here, the individual proposition matters in order to account for its truth-value. It does not require any further sentences to get its truth-value. Thus, it satisfies the atomistic theory of meaning, i.e. meaning of a proposition is understood without relating it with other propositions.
According to the logical positivists, the reason for introducing the verifiability theory is; a) all the statements in a language are divided into two sorts, analytic and synthetic, b) meaning of a statement would be assimilated through our observational sense-data or experiences, c) meaning of a statement is determined by verifiability criterion.
| 1 | This is pointed out by Wittgenstein in his Philosophical Remarks, when he had a conversation with Schlick and Waismann, regarding the issue on verifiability theory of meaning. See, Munitz. M.K. (1981). Contemporary Analytic Philosophy. New York: Macmillan, p. 228. |