From whatever source the poet derives the initial word through which he works, it is a compelling word, seeking to express itself, as it were, in a more defined and concrete word. And as this word exists in both intellect and sense, it is a sensible and spiritual matter which is produced -- images and ideas, and words as signs of these. The binding together of all this matter is the intrinsic form of the poem: a communication of the exemplary word to the poem through this form.
[John Alphonsus Duffy, A Philosophy of Poetry Based on Thomistic Principles, p. 183.]