 Hartley extends these chemical concepts to psychology. As an analogy to the forces of “attraction” and “repulsion,” he writes of both “associations” and “counter-associations” at work in generating the frame of a person’s self. The role of association is obvious—through “joint impression,” it generates “ideas,” including the complex movements that are the basis of the decomplex actions we perform every day. And as we shall see shortly, psychological associations form (“model”) the basic orientations of the self. But “counter-associations” are equally vital. The counter-associations in our dreams, for example, are “of singular use to us, by interrupting and breaking the course of our associations. For, if we were always awake, some accidental associations would be cemented by continuance, as that nothing could afterwards disjoin them, which would be madness” (OM 1, prop. 91). A sane mind, therefore, is one “maintained in a continual round of the production and dissolution”—in, that is, a dynamic balance of connection and detachment, memory and forgetting, that holds out the possibility of change and transformation.