glymour's essay, "freud, kepler, and the clinical evidence", discusses issues involved in experimentally testing psychoanalytic theory. glymour observes that psychoanalysts have opposed evaluating psychoanalysis solely on the basis of statistical hypothesis testing on grounds such as that that the hypotheses tested by experimental psychologists are "often no more than surrogates for the genuine article, and inferences from the falsity of such ersatz hypotheses to the falsity of psychoanalysis are not legitimate." cosin's essay, "critical empiricism criticized: the case of freud", written with c. f. freeman and n. h. freeman, discusses freudian theory in relation to the philosophy of science. cosin, freeman, and freeman criticize the philosopher frank cioffi, arguing that cioffi describes freudian theory as a form of pseudoscience by employing an inappropriate model of science. they note that cioffi builds on the work of the philosopher karl popper.