 Those familiar with the role played by logically proper names in Russell’s philosophy of logical atomism will have an easier time understanding Bolzano’s use of the concept of an intuition. Intuitions are the counterpart in the realm of ideas in themselves to the essentially indexical elements in language: they are best expressed by using a bare demonstrative (‘this’) and, in the case of subjective human intuitions, always have particular contemporaneous mental states as their objects. Any singular idea of a contingently existing particular, moreover, must number intuitions among its parts. Intuitions thus serve as markers of empirical content. 