Considering the first puzzle, a question arises, i.e. how can the non-entity become the subject of a sentence?
In a context where there is no difference between A and B, the phrase 'the difference between A and B' stands for no entity (object). The puzzle involved with regard to this phrase is this. Does the difference between A and B really exist? If we say "Yes", it amounts to ascribing reality to something which is not really there. If we say "No", we are putting an unreal something as the subject of a meaningful sentence when we assert that 'the difference between A and B does not exist'. Now, how does Russell's theory of denoting solve this puzzle? Russell claims that the denoting phrase 'the difference between A and B' is a definite description distinguished from names. A name must stand for some real object when it is a genuine subject of a meaningful sentence, a description need not stand for an object. The puzzle is created by not distinguishing the description from a name. Once this distinction is taken into account, the sentence 'the difference between A and B does not exist' can be analyzed and proved to be a meaningful sentence without ascribing reality to unreals.
If we examine the second sentence "There is no such thing as unicorn", we shall find it does not refer to anything and thereby has no referent. It is so because a concept exists about 'unicorn', but in reality it has no existence. Russell argues that we can imagine the unicorn and therefore we cannot refute our imagination. So 'imagination' is a possible phenomenon. When we imagine, we imagine something thus we cannot imagine nothing and it is not possible to imagine in a vacuum. Imagining something means, some being or something, meaning thereby a referent. Thus, a sentence acquires the meaning by virtue by its referent- it may be a concept or an object. In this sense, Russell expresses that "we must have a robust sense of reality"1.
| 1 | See Russell, B. (1993). Descriptions. in A.W. Moore (Ed.), Meaning and Reference (pp. 46-55). London: Oxford University Press. |