metaphysics

The branch of philosophy that examines the nature of reality, including the relationship between mind and matter, substance and attribute, fact and value.

The theoretical or first principles of a particular discipline.

A priori speculation upon questions that are unanswerable to scientific observation, analysis, or experiment.

Excessively subtle or recondite reasoning.

The science of the inward and essential nature of things.

[Used frequently with the definite article, and generally connected with unpleasant associations, as being a study very dry and at the same time of doubtful truth.

In the Kantian terminology, the science of God, freedom, and immortality. Abbreviated metaphysics

The science of real as distinguished from phenomenal being; ontology; also, the science of being, with reference to its abstract and universal conditions, as distinguished from the science of determined or concrete being; the science of the conceptions and relations which are necessarily implied as true of every kind of being; philosophy in general; first principles, or the science of first principles.