Text 7. Were it possible for logic to be learned through pure cogitation, so that meanings alone would be observed in it, then this would suffice. And if it were possible for the disputant to disclose what is in his soul through some other device, then he would dispense entirely with its expression. But since it is necessary to employ expressions, and especially as it is not possible for the reasoning faculty to arrange meanings without imagining the expressions corresponding to them (reasoning being rather a dialogue with oneself by means of imagined expressions), it follows that expressions have various modes (ahwâl) on account of which the modes of the meanings corresponding to them in the soul vary so as to acquire qualifications (ahkâm) which would not have existed without the expressions. It is for this reason that the art of logic must be concerned in part with investigating the modes of expressions… But there is no value in the doctrine of those who say that the subject matter of logic is to investigate expressions in so far as they indicate meanings…but rather the matter should be understood in the way we  described.[23]