I do not believe in the bundle theory anyway. The bundle theory postulates universals and I do not believe in them; so I do not believe in the bundle theory.

The role of metaphysics in relation to other disciplines, whether philosophical or not and including the natural sciences, is thus a foundational role. Lack of clarity in the concepts of metaphysics implies lack of clarity in other disciplines - both theoretical and practical disciplines - employing those concepts or employing concepts that depend on those of metaphysics.

Knowledge has the form of a tree, and since metaphysics is the most fundamental one of the theoretical disciplines, it represents the roots of the tree.

I would say I was a philosophical boy. Thoughts about 'identical stones' are the earliest philosophical thoughts I remember. But when I was a teenager I also thought about the more typical philosophical problems teenagers think about: the existence of god, the objectivity of morality, whether one can know that the external world exists.

Metaphysics is the study of the most general nature and basic structure of reality, and therefore the concepts of metaphysics, concepts like time, space, identity, resemblance, substance, property, fact, event, composition, possibility, etc., are the most fundamental concepts. Thus metaphysics is the most fundamental theoretical discipline.

Those who take knowledge to be a whole zoo of sub-disciplines will react to my giving metaphysics a privileged position in that zoo or to my thinking of knowledge as a tree, with more and less fundamental parts.

I think there is a metaphysical problem of the relation between mind and body. Thinking that there is no metaphysical dimension to the problem is an error.