Hempel’s philosophy of science in a nutshell—

· All genuinely scientific statements (e.g., laws and theories) must be empirically testable.

· Evidence for or against a scientific hypothesis must be public and objective.

· The testing of scientific hypotheses must occur in accordance with principles of deductive and inductive logic. Such principles do not vary over time or location.

· The testing of scientific hypotheses must be objective—i.e., any competent scientist must be capable of performing the test and interpreting its results.

· Although scientific hypotheses cannot be verified or falsified conclusively, they can in principle be confirmed and disconfirmed to varying degrees of confidence.

· The degree to which a scientific hypothesis is confirmed or disconfirmed by a body of evidence is an objective matter. Disputes among scientists can in principle always be rationally resolved.

· Although some scientific terms (particularly, theoretical terms) cannot be explicitly defined, all such terms must be empirically meaningful. I.e., they receive meanings as components of the system of internal principles and bridge principles by which they are connected to our experience of the world.

Thomas Kuhn, The Structure of Scientific Revolutions

· Disagrees with Hempel on several important questions

· Believes that Hempel’s account of the way science is done is inconsistent with the history of science

· Denies that the testing of scientific hypotheses is entirely objective and that scientific disputes can, even in principle, always be rationally resolved

· Believes that scientific change occur in a recurring historical pattern, the stages of which can be identified and described

· Believes that scientific change is sometimes revolutionary (i.e., discontinuous and chaotic) rather than steady, continuous, and “logical”

· To really understand what science is and how it operates, we must understand what scientific revolutions are and how they occur (hence, the title of his book)

· There is no single scientific method that extends over the entire history of science. Rather, scientific revolutions often bring with them a new conception of what science is and how it should be conducted.

· Progress in science must be understood in terms of the recurring pattern of scientific change and not as a steady process of accretion (accumulation of data and resulting confirmation/disconfirmation of laws and theories).