The sciences progress by leaps and bounds. For many people, scientific advance is the very epitome of progress. If only political or moral life could be like that! Scientific knowledge is cumulative, building upon previous benchmarks

One has to acquire an “ability to see resemblances between apparently disparate problems.”34 Yes, textbooks present lots of facts and techniques. But they do not enable anyone to become a scientist. You are inducted not by the laws and the theories but by the problems at the ends of the chapters. You have to learn that a group of these problems,

These three classes of problems—determination of significant fact, matching of facts with theory, and articulation of theory—exhaust, I think, the literature of normal science, both empirical and theoretical. They do not, of course, quite exhaust the entire literature of science.

Kuhn cannot take seriously that “there is some one full, objective, true account of nature.” Does this mean that he does not take truth seriously? Not at all. As he observed, he said nothing about truth in the book, except when quoting Bacon (169). Wise lovers of facts, who try to determine the truth about something, do not state a “theory of

More clearly than most other episodes in the history of at least the physical sciences, these display what all scientific revolutions are about. Each of them necessitated the community’s rejection of one time-honored scientific theory in favor of another incompatible with it. Each produced a consequent shift in the problems available for scientific

Normal science does not aim at novelty but at clearing up the status quo. It tends to discover what it expects to discover. Discovery comes not when something goes right but when something is awry, a novelty that runs counter to what was expected. In short, what appears to be an anomaly. The a in anomaly is the a that means ‘not’, as in ‘amoral’ or

To be accepted as a paradigm, a theory must seem better than its competitors, but it need not, and in fact never does, explain all the facts with which it can be confronted.

Without the special apparatus that is constructed mainly for anticipated functions, the results that lead ultimately to novelty could not occur. And even when the apparatus exists, novelty ordinarily emerges only for the man who, knowing with precision what he should expect, is able to recognize that something has gone wrong. Anomaly appears only

The book ends with the disconcerting thought that progress in science is not a simple line leading to the truth. It is more progress away from less adequate conceptions of, and interactions with, the world (§XIII).