This book offers a detailed study of the truth-bearers problem, that is, the question of which category of items the predicates 鈥榯rue鈥?and 鈥榝alse鈥?are predicated. The book has two dimensions: historical and systematic. Both focus around Tarski鈥檚 semantic theory of truth. The author locates Tarski鈥檚 ideas in a broad context of Austrian philosophy, in particular, Brentano鈥檚 tradition. However, Bolzano and phenomenology (Husserl and Reinach) are also taken into account. The historical perspective is completed by showing how Tarski was rooted in Polish philosophical tradition originated with Twardowski and his version of Brentanism. The historical considerations are the basis for showing how the idea of truth-bearers as acts of judging was transformed into the theory of truth-bearers as sentences. In particular, the author analyses the way to nominalism in Polish philosophy, culminating in Lesniewski, Kotarbinski and Tarski. This book is indispensable for everybody interested in the evolution of Austrian philosophy from descriptive psychology to semantics. It is also a fundamental contribution toward a deeper understanding of the philosophical background of Tarski鈥檚 theory of truth.