The second axis of this research project will deal with the historical evidence supporting our thesis according to which Brentano’s descriptive psychology was construed as a research rather than as a system of philosophy.
The first kind of historical evidence involved here is genetic and it involves the development of DPRP from Brentano’s early considerations of the role of phenomenology in the system of metaphysics (1860s) to the formulation of DPRP proper in the Vienna period. Brentano’s first mention of what will be later called descriptive psychology dates back to the Würzburg period, in the late 1860s. Interestingly, Brentano first used the term ‘phenomenology’ to characterize research into the contents of our mental states, only later (in Vienna) expanding the lexicon of the discipline with the expressions ‘descriptive psychology’, ‘psychognosy’ or ‘phenomenognosy’. As a part of metaphysics, phenomenology was then introduced as a propaedeutic to ontology, following the so-called ‘transcendental philosophy’¾the part of metaphysics dealing with skepticism and the arguments against it. In this context, phenomenology was introduced as an ‘investigation on the contents of our presentations’ (M96, 31739), dealing with phenomena, both mental and physical, as opposed to what exists outside the mind. With the exception of individual contributions, the motivation for Brentano’s introduction of phenomenology into metaphysical investigation is still largely unknown today. The works of John Stuart Mill¾both his systematic work and his book on Auguste Comte’s positivism¾and William Whewell made a strong impression on the young Brentano and may have influenced this introduction. Indeed, the distinction between explicative-causal (aetiological) and descriptive (phenomenological) sciences proposed in Whewell (1847) is palpable in Brentano’s early manuscripts on the classification of sciences. Moreover, this distinction also played a role later on, in Brentano’s explanations of the role of descriptive psychology in his Viennese lectures, which rely on a distinction between geognosy and geology to illustrate the distinction between phenomenology (also called phenomenognosy, psychognosy or descriptive psychology) and psychology more generally. On the basis of these manuscripts, it seems that Brentano maintained a relatively coherent conception of phenomenology, or descriptive psychology, and of its role in relation to psychology in general as well as to metaphysics, from the early Würzburg period up to the 1900s. A close investigation of these manuscripts, as a part of the project of reconstructing DPRP, would therefore call into question some of basic assumptions concerning the development of descriptive psychology in Brentano’s work. According to Kraus (1919, 21), Kamitz (1988, 60), Bergmann (1966, 361), and more recently Antonelli (2008, XVII), Brentano would have developed the idea of descriptive psychology first in the late 1880s in Vienna, breaking with his earlier conception of psychology as a Einheitswissenschaft (unitary science). The proposed research would allow a revision of these claims about the origins of DPDR, and would thereby set the ground for the research into A2. More concretely, this part of the research project would involve a reconstruction of the content of the idea of descriptive psychology from an historical perspective, focusing mainly on manuscripts and relevant correspondence. It would also show how the phenomenology that was introduced in the late 1860s was developed into descriptive psychology as a research program. In this context, Brentano’s opposition to concurrent theories and paradigms in psychology will also be considered. (most prominently the experimental psychology of Wundt (Wundt 1874) and the psychophysics of Fechner (Fechner 1860)).
The second kind of historical evidence involved in this axis of the research project concerns the ‘protective belt’ of auxiliary hypotheses of DPRP. In the literature on the history of the school of Brentano, it has been customary to make a distinction between the orthodoxy of the school and the outsiders, who didn’t belong to the school in the full sense of the term. This distinction has historical reasons: Brentano did want to build a philosophical school, as many letters, essays, and documents attest, and he was highly irritable when his students developed theories that diverged even so slightly from his convictions. These convictions soon formed the kernel of the orthodox doctrine, defended first by Anton Marty in Prague, and later by Marty’s students, among others by Oskar Kraus and Alfred Kastil, who cultivated the strict obedience to the orthodox doctrine in their editions of the posthumous works of Brentano and in their own philosophical work. This sharp distinction between the outsiders and the orthodoxy has influenced considerably the historical work on the school of Brentano and the philosophical movements that emerged from it. Husserl himself used this distinction in order to disconnect his phenomenology from Brentano’s descriptive psychology. Meinong used a similar strategy to underline the independence of his theory of objects. However, at bottom, Husserl’s phenomenology (at least in his early version) and Meinong’s theory of objects belong to DPRP; they constitute, together with Stumpf’s theory of tonal fusion and Ehrenfels’ Gestalt qualities – two further ‘dissident theories’–, the protective belt of auxiliary hypotheses of DPRP. In (A2b), the research project will investigate the set of auxiliary hypotheses developed by Husserl, Meinong, Stumpf, and Ehrenfels, and evaluate the nature of their contribution to DPRP.
 See Brentano’s lectures on metaphysics (M96). On the introduction of phenomenology into Brentano’s metaphysics, see also Baumgartner (1989a) and Tiefensee (1998, 185f).
 Brentano had an annotated copy of the History of Inductive Sciences in his library, as well as one of Mill’s book on Comte (the French translation by Clémenceau). See Mill (1868).
 See, for instance EL75, 12921–12, where the distinction between descriptive (beschreibende) and causal (nach Wirkungen) sciences. This distinction also played a central role in Schlöder (1852), another work that Brentano owned and annotated heavily. The distinction between science of objects and science of phenomena is discussed in Schlöder (1852, xxv) and referred to by Brentano in EL75, 12921–12.
 See Brentano (1982, 6) and Brentano (1895, 34).
 See, for instance, the manuscript Ps 86, dated from 1901, which deals with psychognosy in a similar way to Brentano before in the 1880s in Vienna.
 In Fréchette (2012), I put forward further arguments against the ‘late discovery’ interpretation of descriptive psychology.
 On auxiliary hypotheses, see Lakatos (1978, 179f.).
 On this intention, see Fisette & Fréchette (2007).