 Still, there is an important qualification in Feigl’s account of realism. This qualification has to do with the fact that Feigl takes pains to separate his own semantic-scientific realism from traditional metaphysical realism. By metaphysical realism, Feigl means all attempts to systematically employ “transcendent, i.e., in principle untestable, assertions” (Feigl 1956, p. 22). By his own account, however, the testability or confirmability of an assertion is the crucial criterion for its being meaningful. Feigl writes: