 The widely perceived collapse of the classical Viennese project to find in an empiricist meaning criterion a demarcation criterion against metaphysics—we reserve judgement about Carnap’s last two proposals here—can be interpreted in a variety of ways. It strongly suggests that cognitive significance cannot be reduced to what is directly observable, whether that be interpreted in phenomenalist or intersubjective, physicalist terms. In that important but somewhat subsidiary sense, the collapse spelt the failure of many of the reductivist projects typically ascribed to Viennese neopositivism (but see section 3.3 below). Beyond that, what actually had failed was the attempt to characterize for natural languages the class of cognitively significant propositions by recursive definitions in purely logical terms, either by relations of deducibility or translatability. What failed, in other words, was the attempt to apply a general conception of philosophical analysis as purely formal, pursued also in other areas, to the problem of characterizing meaningfulness.