What field of study is concerned with reasoning principles and methods?

The field of study that is specifically concerned with reasoning principles and methods is logic. Logic systematically explores the nature of valid reasoning and argumentation, establishing the rules and structures necessary for differentiating sound arguments from unsound ones. It examines how conclusions can be derived from premises through various forms of inference, both deductive and inductive.

Logic has a foundational role in philosophy and critical thinking, providing tools that enable individuals to analyze and construct arguments effectively. It encompasses various branches, including symbolic logic, modal logic, and propositional logic, each contributing insights into reasoning processes.

In contrast, the other fields listed do not focus directly on reasoning principles. Epistemology is concerned with the nature and scope of knowledge, investigating questions about belief, truth, and justification. Ontology studies the nature of being and existence, addressing what entities exist and their categories. Metaphysics deals with the fundamental nature of reality, including concepts like time, space, and causality. While these areas may intersect with logic, they are not primarily concerned with the formal principles and methods of reasoning itself.