Of course, the human psyche does not have the shape of an octahedron, nor any shape at all; and the foregoing figures merely illustrate the theories of certain European psychoanalysts. As useful as they are to the rhetor (and we will see that they do have their utility), what is ultimately pertinent to our task is the actual human psyche itself.
As contemporary Psychology tells us, this is not quite what Freud and Jung believed it to be; and these days psychologists typically explain the psyche in terms of the functions of different brain components. Such brain structures as the Reticular Activating System (that arouses the brain), or the Limbic System (the center of our Emotions), are what are pertinent; and the image on the right gives the mental counterpart of the main brain components. Here we find: Arousal, Emotion, Sensation, and Language, as well as the representation of these in the higher cortex in the form of Ideation, Thinking, and Memory. It is to this landscape (along the contours of the psychological types, to be sure), that we as rhetors must speak, and to which we must address our appeals, in whatever ways we craft them, if we wish to persuade.