In this regard, two issues are raised here relating to the meaning of a proposition and the determination of its truth-value. They are:

How does meaning help to determine the truth-value of a proposition?
How is it possible for a hearer to understand the sense of a proposition where the constituent parts of the proposition are completely new for him?

In response to the second question, Russell states that to know the meaning of a proposition is to understand the proposition what it states about. Hence, we have the knowledge of that proposition. On his account, we are acquiring knowledge through two ways. One is through 'knowledge by acquaintance' and another is through 'knowledge by description'. The first one expresses that we know the meaning of a proposition when we know the meaning of its each constituent word and what they designate. It simply means that we are acquainted with the constituent words of a proposition. In this case, meaning of a proposition can be known independent of its truth-value. But this is not the case with the second one, i.e., 'knowledge by description'. It states that to know the meaning of a proposition is to know the conditions under which the proposition is treated as true or false. Hence, we know the meaning of a proposition through its description of the object that it states. Applying the same procedure we can understand the meaning of a proposition even though the constituent words are new to us. The description of a proposition lies in its presupposition, i.e., to describe a proposition is to know what it presupposes in a particular context. This envisages that each proposition must have logical character to satisfy the propositional attitude¹ and describes how it is used in a particular context of our discussion. With all these features there will be no hurdles for us to understand the meaning of a proposition.

In order to explain how a proposition acquires it meaning, Wittgenstein introduces a new theory called 'Picture theory of meaning'. He states that "a proposition is a picture of reality: for if I understand a proposition, I know the situation that it represents" (Tractatus, 4.021). This simply means to understand a proposition is to know what it represents or what it states about. Some problems may be encountered when we analyze the meaning of a proposition and its relation to truth conditions. For example, consider an elementary proposition where the constituent words are the proper names. The question arises, how will we get the truth-value of an elementary proposition? Mere names can neither state a fact nor any state of affairs. A name cannot be judged as either true or false. This we will be discussed when we bring the topic of elementary proposition.

Focusing on the second question further, i.e., 'how do we understand a proposition which we have never come across before?' This question can be answered through an analogy. The analogy is as follows. Suppose, it is a situation where there is a small town and some people of that town are dacoits. Though a few of them are dacoits, yet all the people in that town maintain intimacy with each other and they have a strong feeling of togetherness. So in order to alert those dacoits of the police, the town people made some conventional signs. For instance, 'green cloth means the presence of police are entering into that town', 'yellow cloth means police left that town', 'red cloth means someone is caught by police'. No outsider can understand what those clothes stand for by simply looking at a particular colour of cloth unless someone of that town explains the significance behind a particular colour of cloth. On this analysis, we find that though all these signs are having some specific meanings yet one who does not belong to that town can make out some sense after seeing a particular colour of cloth hanging across that town. This is possible if an outsider is having certain knowledge about the sign and its significance. In addition (s)he must have some commonsense to understand certain things within its context. One can ask, what makes the outsider to make out the sense from the new sign? In a similar fashion, how is it possible for an individual to understand the sense of a proposition where the constituent words are new for him? All such problems could be resolved if we analyze Wittgenstein's picture theory of meaning.

¹	Here, the phrase 'propositional attitude' is understood as the way in which a proposition is constructed, and shows its significance when it is analyzed in a language system.