[92] Of our vivifying power, therefore, of which the blood is, as it were, the essence, one portion has particular honour, namely, that of speech and reason; I do not mean the stream which flows through the mouth and tongue, but I speak of the fountain itself, from which the channels of utterance are, in the course of nature, filled. And this fountain is the mind; by means of which, all our conversations with and cries to the living God take place, at one time being voluntary, and at another involuntary.