Metaphysics consists of four areas of inquiry. (1) First principles concerns the indispensable building blocks and axioms that make philosophical inquiry possible to begin with. (2) Ontology concerns the nature and structure of being, existence, or reality. (3) Cosmology concerns the nature and structure of the observable universe. (4) Theology concerns whether any deities or higher powers exist and, if they do, their nature and relationship to the universe.

My main area of interest in philosophy is ethics. However, it is important to frame any discussion of any other area of philosophy, including ethics, in terms of metaphysics. This is true for several reasons. First, it is not possible to engage in any philosophical discussion without first establishing the principles that govern and limit human thought. Therefore, first principles must be discussed. Second, the natural universe imposes clear limitations on what is achievable. While these limitations do not necessarily dictate what is good, bad, or evil, they may well preclude some of the possible means of doing the good and avoiding the bad. Thus, an understanding of cosmology is indispensable to any ethical inquiry. Third, if one or more gods exist, this would potentially answer fundamental questions about why humans exist and what goals humans ought to pursue, depending on the degree to which god(s) interact with humans and the degree of clarity with which they reveal their expectations. Therefore, theology is potentially relevant to ethics and worthy of discussion for a person whose primary area of interest in philosophy is ethics. Fourth, the nature of being or existence is potentially relevant to ethics because what is the case could potentially determine how people ought to act and think. Thus, ontology is also potentially relevant to ethics and worthy of discussion.