" is a description, "
is unreal" or "
does not exist" is not nonsense, but is always significant and sometimes true.
We may now proceed to define generally the meaning of propositions which contain ambiguous descriptions. Suppose we wish to make some statement about "a so-and-so," where "so-and-so's" are those objects that have a certain property
, i.e. those objects
for which the propositional function