 It has been suggested that Brentano’s fourth Habilitations-thesis makes him an advocate of a particular version of the unity of the sciences, according to which there is a unity of method (cf. Haller 1993, 27) and that it stands in contrast to “Dilthey’s view according to which the so-called Geisteswissenschaften or human or moral sciences would somehow call for a special method of ‘understanding’ or Verstehen, as opposed to the ‘explanation’ of the natural sciences.” (Smith 1994, 31). One has to be cautious not to overstate this point, though. While it is true that Brentano uses both the terms “method” [methodus] and “natural science” [scientiae naturarum] in the singular, there is strong evidence that he had a minimal understanding of what this method should exactly consist in. He never suggested that all scientific disciplines could be reduced to other, more basic disciplines, nor did he argue that all natural sciences should apply exactly the same method, nor that mathematization or the use of a formal language was indispensable for scientificity. For Brentano, a method counts as scientific as long as it fulfills the minimal requirements of applying observation, description of facts, and induction. The specific methodological procedures applied in a given scientific discipline depend first and foremost on the objects studied: