Dr. Mender’s first point is that the experimental method cannot adequately confirm or reject scientific hypotheses. This view has been articulated in the "Duhem-Quine thesis" and is based on the assumption that hypotheses cannot be tested in isolation from the theoretical network in which they belong (1, 2). Scientists do not subject an isolated hypothesis to testing but only a whole group of hypotheses. Thus, testing a hypothesis depends on its background assumptions. When the background assumptions are challenged, the observations that initially were used to justify a hypothesis become irrelevant. However, when a predicted event fails to occur, it is evident that something in the hypothesis needs to be changed, but nothing in the experiment indicates what the change should be. Consequently, any hypothesis can be safeguarded from falsity, so long as scientists are prepared to make appropriate adjustments to other parts of the theoretical framework. Therefore, critical experiments alone may be inadequate to change the zeitgeist of science.