It's from a philosophy book, he calls the superid the missing elemental piece of Freud's model:

Where the superego is driven by resolve, the superid is drawn by passion. In the emotional self-control carried out by the superid the person follows her reflexive desires, attracted by an appealing style of life or repelled by a disgusting one. One who is self-conscious in the consummatory mode is reflexively aware of the inherent appeal of various forms of action. The superid guides the self while remaining as committed to the “pleasure priniciple” as the id. Where the superego makes a rational commitment to certain principles and policies, the superid makes an emotional identification with certain manners and a style. It is as if in the superego the person declares to herself, “I will do this or that,” where in the superid she says to herself, “I am that kind of person.” In the superego one pushes along with determination as commanded; in the superid one flows ahead in forms that intrinsically appeal. As a result, unlike prudently following policies or rules, acting with an around good form releases one into action. In it one flings herself into life because the source of the energy is what she deeply wants to do. Passion for a lifestyle is the analog to will power. Yet this is still self-control – intended effects are consistently produced in oneself when pursuing self-referential images as they are when applying policies or rules. Those who can act with flair in their superids possess charisma and cause a stir.
Where a sense of pride in the form of self-respect is the positive emotion arising from conformity with the superego’s commands, a sense of pride in the form of self-esteem is the positive emotion from successfully meeting the superid’s expectations. Where guilt is the negative emotion accompanying violation of the superego’s commands, self-disgust is the negative emotion accompanying violation of the superid’s imperatives. In guilt one chastises himself for the wrong he has done. In self-disgust he turns away from himself for the tastelessness of his action. One is punished by guilt and sickened by self-disgust.
The superid is ordinarily on relatively good terms with the id, permitting it gratification to the extent of good form while guiding it in appropriate directions. If one’s desire to be a certain kind of person or live a certain style of life is sufficiently strong, this simply out-pulls the more basic desires rather than stifling them. The superid- which grows out of the id as the superego grows out of the ego – doesn’t fight desire when the id is lured by the distasteful or vicious, it merely turns away in disgust. The superid marginalizes the id when necessary but does not punish it. Where the superid tends to have more difficulty is with the ego. Easily offended by the Ego’s forms of action, the superid is oblivious to its logic and naturally profligate with resources. Where the excesses of the superego may bring emotional problems, those of the superid may bring financial problems.

The superid is the major elementary sector of the personality omitted by Freud. Recognition of the superid clarifies some of the inconsistencies and anomalies in Freud’s analysis. To Freud the superego was composed of the conscience and the “ego ideal,” the latter being an unverbalized image of what we would like to be. However such an image is patently part of a consummatory function having everything in common with the id except reflexivity and nothing in common with the superego but reflexivity. Freud did anticipate portions of what belongs to the superid with his notions of the ego-ideal, sublimation, and the “narcissistic type” (in which, as he puts it, there is little tension between ego and superego but instead “personality” and the capacity for vigorous action); but he never recognized a separate, reflexive, emotionally based constituent and sector of the developed personality, and he had no inkling of its central importance. All of these elements were instead lumped together incoherently with the superego.

Some might be tempted to see only narcissism in the superid, but narcissism is a narrower concept than that of the superid. Narcissism is a pathological manifestation of individualism and amorality in which smugness, meaningless and lack of emotional connection mingle in a prominent superid. But under such circumstances the superego is no healthier than the superid and manifests analogous disorders. Narcissism could no more be the essence of the superid than smug self-righteousness could be the essence of the superego. When a relatively well-adjusted young person absorbs manners and lifestyle in emulation of the models around her or independently fashions them in a normal way, a superid, not narcissism, is developed. The superid exercises a basic form of self-control, one that is preceded the superego historically and one by no means inherently less healthy, worthy, or important than that of the superego. Understandably, some clinicians have emphasized related pathological forms, but the superid as a sector should not beimpugned. Nor can narcissism itself be properly understood without grasping the nature of the superid and its place in the personality. Absent a distinction between the superego and superid, psychoanalysts have attempted to fit the phenomenon of narcissism into the superego, but in doing so have muddled both concepts.