 This suggests that a hard core of Viennese anti-metaphysics survives the criticism and subsequent qualifications of early claims made for their criteria of empirical significance, yet retains sufficient philosophical teeth to remain of contemporary interest. The metaphysics which the left wing attacked, besides everyday supernaturalism and the supra-scientific essentialism of old, was the correspondence conception of truth and associated realist conceptions of knowledge. These notions were deemed attackable directly on epistemological grounds, without any diversion through the theory of meaning: how could such correspondences or likenesses ever be established? As Neurath liked to put it (1930), we cannot step outside of our thinking to see whether a correspondence obtains between what we think and how the world is. (Against defenses of the correspondence theory by arguments from analogy it would be argued that the analogy is overextended.) Against the counter that this is merely an epistemic argument that does not touch the ontological issue Neurath is likely to have argued that doing without an epistemic account is a recipe for uncontrollable metaphysics.