"We may … have to relinquish the notion, explicit or implicit, that changes of paradigm carry scientists and those who learn from them closer and closer to the truth." (Thomas Kuhn, Structure, p. 232)
Just as most politicians, hopefully, go into politics driven by passion for social justice, most scientists enter their field in pursuit of the truth. But we all know what happens to politicians after they get elected the first time. They quickly realize that the working realities of holding public office requires them to "compromise", often setting their high ideals aside. To stick to principle is to be without influence. Kuhn tells us something similar about scientist: once they enter their chosen field they are faced with the task of "solving the problems or puzzles that its paradigms define" (228); they are not tasked, let's say, with simply "discovering the truth". While they can to a certain extent pursue their own interests and satisfy their curiosity, they are beholden to a powerful set of community commitments that determine what it is possible to discover at any given time. No matter how true a scientist's hunch may be, it may be impossible to demonstrate that truth to the community because to acknowledge it will be, well, revolutionary. It will undermine the authority of those with power and therefore tear the community apart. In that sense, what Kuhn calls "normal science" is a bit like realpolitik.
On Monday, I said that there is something disturbing about this insight, even though it seems entirely unavoidable to the "mature" mind who knows anything about social life. Perhaps it is precisely the prospect of maturity, adulthood, that disturbs the sensitivities of the young researcher who thought science was the stubborn pursuit of truth above all else. Kuhn's call for us to grow up, then, is rather stark: "Inevitably [these] remarks will suggest that the member of a mature scientific community is, like the typical character of Orwell's 1984, the victim of a history rewritten by the powers that be."