Includes bibliographical references and index.

Theories and falsification -- The logic of falsification -- The limits of falsification -- Are there crucial experiments? -- Falsification and the method of difference -- The rejection of theories -- Popper's methodological falsificationism -- Responses to prima facie falsifying evidence -- The replacement of theories -- Whewell on scientific progress -- Kuhn on theory replacement -- Lakatos on progressive research programs -- The asymptotic agreement of calculations -- The acceptability of theories -- Successful prediction and the acceptability of theories -- Variety within evidence -- Other factors in theory evaluation.