The greater part of Edmund Husserl's Ideas II is a regional ontology explicating, in order, the regions of material nature, animal nature, and the spiritual world that in good detail defines them individually, distinguishes them from each other, and explores the manner of their interrelation.1 This work gives the initial impression of being a research manuscript outlining or opening up three important regions that could be the basis for further, more specific phenomenological descriptions. The final chapter, however, explicitly makes the argument that the spiritual world has ontological priority over the naturalistic world.2 Argumentation is commonly conceived of as being foreign to phenomenological research, but the final section of this chapter makes it clear that Husserl is also attempting to convince nonphenomenologists of this position, thus arguments are required.3 The order in which the regions are explored and the consistency and kind of examples employed makes it clear that the non-phenomenologists Husserl has in mind are those belonging to the natural-scientific community in general and psychologists specifically. The point of the argument is to show that to do naturalistic psychology or any other natural science without considering the contribution of the spiritual world is not only naive, but dangerous.4 In this essay, I will concentrate on clarifying the arguments that Husserl makes for the priority of the spiritual world over the naturalistic with the aim of making phenomenology convincing to nonphenomenologists, or at least showing how this can be done. In Ideas II, Husserl presents two general arguments for the priority of the spiritual world over the naturalistic. The first is what could be called the transcendental or constitutive argument. In this case, the point is made that spirit has an absolute existence, while nature is relalive in the sense that it is constituted by spirit. The second is an argument posed by Husserl specifically against the psychological theory of psychophysical parallelism. According to this theory, the mental and physical are parallel realms in the sense that for every physical stimulus of the human body, specifically the sense organs, brain, and neural network connecting them, there is a parallel event in consciousness, such as a sensation or idea.5 The point of Husserl's argument is to demonstrate that this relationship is not strictly parallel; while there are many important parallels, there are profound aspects of consciousness for which there are no physical correlates. Coming to accept this point leads back to the first argument establishing the constitutive priority of the spiritual world. Thus, if nonphenomenologists could be convinced of this second argument, the first would be implicit and thus rendered more approachable. Given the history and tradition of the natural sciences, it is difficult to imagine that such scientists would even pause to consider the transcendental argument, much less come to accept it. Long ago the natural sciences had declared their independence from philosophy, turning instead to the materialist ontology and inductive-empirical method of physics.6 To make the general claim that the spiritual world has ontological priority over the one studied by the natural sciences would seem from their point of view to be a step backwards and preposterous. The spiritual world is the subjective orpersonalistic world of objects and values encountered in mundane living. It includes practical objects and affairs occupying individuals and society, pleasures and pains, likes and dislikes, motivations, and, in short, all the meanings of everyday existence.7 These are subjective affairs and, clearly, subjectivity is exactly what the natural sciences are attempting to control if not eradicate altogether in order to be radically objective. Another difficulty for the natural scientists certainly would be Husserl's use of the "world annihilation" thought experiment as evidence to back up the constitutive argument. …