Metaphysics Glossary

Knowledge that depends on sensory experience or empirical evidence for its justification.

Knowledge that is justified independently of sensory experience, such as mathematical and logical truths.

An entity that does not exist in space or time and has no causal powers, such as numbers, sets, or propositions.

The relation between events where one event (the cause) brings about another (the effect).

The thesis that free will is compatible with determinism; agents can act freely even in a determined universe.

A truth or entity that could have been otherwise; it exists or holds but not by necessity.

The doctrine that every event is necessitated by antecedent causes and the laws of nature.

The view that reality consists of two fundamentally distinct kinds of substance, typically mind and matter.

The phenomenon where higher-level properties arise from lower-level interactions but are not reducible to them.

The doctrine that objects possess essential properties that define their identity and nature.

The view that all points in time -- past, present, and future -- are equally real.

The state of being real or having being. A central concept in ontology and a subject of deep philosophical debate.

The capacity of agents to choose and act among genuine alternatives, unconstrained by external compulsion.

The metaphysical position that reality is fundamentally mental or constituted by ideas and minds.

The formal study of the relations between parts and the wholes they compose.

A system of logic that deals with necessity, possibility, and related concepts using possible-worlds semantics.

The view that reality is ultimately composed of one fundamental kind of substance or principle.

A truth that holds in all possible worlds and could not have been otherwise.

The view that universals or abstract objects do not exist; only particular concrete things are real.

The study of being, existence, and the fundamental categories of what there is.

The thesis that everything is physical, or supervenes on the physical.

A complete and consistent way things might have been; used in modal logic to analyze necessity and possibility.

The subjective, qualitative aspects of conscious experience, such as the redness of red or the painfulness of pain.

A fundamental, independently existing entity that bears properties and persists through change.

A dependency relation where higher-level properties cannot differ without a difference in lower-level properties.