These modes of expression are only instrumental to an inner process in man, namely, thinking or feeling . Spinoza, by a stroke of genius, described the evolution of the ratio as an evolution of acquiring and developing a more and more sophisticated tool, that is, our mind , by using and refining it. Therefore thesis A is wrong, because we can think everything we want, even though it may not be expressible in language. A good example is the experience of the mystics. Although they have an absolutely clear experience and knowledge in their mind, the language is inadequate and too restricted to become a vessel of expression of their most intimate and comprehensive experience or thinking.
Ideas are much more complex than the simple components of a language.
Although our vocabulary expands continuously, the single words are linked to a precise meaning or several different but yet clear meanings. Poets try to exploit the farthest edges of our language and to express what seems inexpressible. This kind of language is open to a vast degree of interpretation and could hardly be used to communicate in everyday life. It is an artistic expression of inner moments of personal experience. It is possible, through the intimations given in poetic language, to transcend the narrow boundaries of language and to reach the original experience or idea, the poet or philosopher or mystic tried to express through the available means of a language.