3. Which make mental or verbal propositions.
To form a clear notion of truth, it is very necessary to consider truth
of thought, and truth of words, distinctly one from another: but yet it is very difficult to treat of them asunder.
Because it is unavoidable, in treating of mental propositions, to make use of words: and then the instances given
of mental propositions cease immediately to be barely mental, and become verbal. For a mental proposition being
nothing but a bare consideration of the ideas, as they are in our minds, stripped of names, they lose the nature of
purely mental propositions as soon as they are put into words.