 The distinction between content and object of a presentation was not new in Twardowski's time. It was the most fundamental element of Bolzano 1837; it was later present in works of Bolzanian inspiration (Zimmermann 1853, Kerry 1885–1891; on Zimmermann see Winter 1975, Morscher 1997, Raspa 1999); and it was also mentioned in works of Brentanian inspiration (Höfler and Meinong 1890, Hillebrand 1891, Marty 1884–1895: article 5, 1894). Nevertheless, the distinction was by no means common lore. In particular, before Twardowski, no Brentanian had endorsed the distinction between content and object in a way that offered a basis for solving the problems of Brentano's theory, nor had anyone among the Brentanians devoted any in-depth study to the issue, although the differences between Bolzano's and Brentano's theories are such that reworking the distinction in a Brentanian framework raises philosophical problems that are by no means trivial. A major difference concerns the role of the content of a presentation and its ontological status, since for a Brentanian the content of a presentation can only be something actually existing in one's mind. No Brentanian had thus realised in full the implications that reinterpreting the Bolzanian distinction in a Brentanian key would have. Carrying out this task, and thus helping Brentano's theory out of its most pressing troubles, was Twardowski's original contribution. He drew inspiration from arguments in favor of the content-object distinction present in Bolzano, but he reinterpreted them in a Brentanian framework to sustain conclusions that were opposite to Bolzano's and that were new for the Brentanians. One such conclusion, and a major implication of Twardowski's theory of intentionality, is that there are no objectless presentations, presentations without an object, no matter how strange and improbable that object  is[4].  Even presentations of contradictory objects have both content and object. It is this thesis and the conclusions that Twardowski drew from it that have had a major impact on the development of Brentanian theories of intentionality and that opened the way to ontologies as rich as that of Alexius Meinong. On the other hand, this position, together with Twardowski's identification of meaning with psychological content, prompted Husserl's critical reactions and led Husserl to the theory of intentionality set out in the Logical Investigations (1900/01) where Twardowski's distinction between content and object is taken up (on this, see Schuhmann 1993; on Twardowski's influence and ‘triggering effect’ on Husserl, see Cavallin 1990, especially 28f). Twardowski's ideas were not only influential on the continent. Via G. F. Stout, who published an anonymous review of Content and Object, in Mind, Twardowski's ideas had an influence on Moore and Russell's transition from idealism to analytic philosophy (van der Schaar 1996).