Return to note 16 By public, I refer to any social situation involving more than one person. Thus, shaming even within the relatively private domestic sphere is “public.”
Return to note 17 Rather than connoting something undesirable, the phrase “negative feedback” in physiology is intended to suggest reversal of direction in a process. This reciprocating relationship involves small adjustments to maintain a steady course. Like a tightrope walker’s hold on the bar, a negative feedback cycle steadies a normal process by applying check-and-balance reactions to achieve balance or homeostasis. A system with negative feedback as a standard feature acts to maintain or produce neither too much nor too little of the necessary ingredients for health. For example, to reduce body temperature, the body perspires. Perspiring dehydrates the body, so the body sends a signal of thirst. Drinking satisfies the thirst and the dehydration and may cool the body as well. As can be seen in the analogy of the tightrope walker, a negative feedback cycle is never static but rather always in motion—though certainly with less purpose than the high wire performer’s. On the other hand, the phrase “positive feedback” does not connote, most often, a desired outcome, but rather a normal process unchecked and usually not reversible without externally applied measures. (One desired positive feedback cycle is the expulsion of a baby from the uterus.) Let us return to the example of high body temperature. While a fever is a natural response to infection, a fever that raises body temperature above that body’s tolerance threshold can cause a seizure; therefore, an adult will intervene before the critical temperature is reached by either taking aspirin or a cool bath, or even seeking medical help. If the person with a fever is unable to care for herself (e.g., is very young or very old), a caretaker must intervene when the fever is rising to the critical temperature. Unless someone attends to the fevered body’s need, a positive feedback cycle will ensue until either the fever breaks or the patient is severely damaged or dies. Likewise, a patient with uncompensated shock, shock that has shifted from a negative feedback cycle to a positive feedback cycle—including emotional shock—can result in a person’s death without appropriate external care just as a tightrope walker who has adjusted too far can fall to her death—unless a net is in place.