Time and Persistence
This area concerns the nature of time and how objects manage to persist through it. It asks whether time genuinely passes, whether past and future are real, and how a thing can change yet remain one and the same.
Definition
The metaphysics of time and persistence studies the structure and reality of temporal passage and the conditions under which an object or person remains numerically the same across time.
Scope
Covers the metaphysics of time, the A-theory and B-theory of time, presentism and eternalism, the problem of persistence and change, the endurance-perdurance debate, and personal identity through time.
Sub-topics
Core questions
- Does time really pass, or is passage an illusion?
- Are the past and future as real as the present?
- How can a thing change yet remain the same thing?
- What makes a person at one time identical to a person at another?
Key concepts
- Temporal passage
- A-series and B-series
- Presentism
- Eternalism
- Temporal parts
- Endurance
- Perdurance
- Psychological continuity
Key theories
- A-theory versus B-theory
- Following McTaggart's distinction, A-theorists hold that the present is metaphysically privileged and time genuinely passes, while B-theorists hold that temporal reality consists of tenseless earlier-than relations with no objective passage.
- Perdurantism (four-dimensionalism)
- Objects persist by having temporal parts spread across the times they exist, so a persisting thing is a four-dimensional whole; Lewis and Sider defend this against endurantism.
- Reductionism about personal identity
- Parfit argues that personal identity over time consists in psychological continuity and connectedness, and that what matters in survival is this continuity rather than a deep further fact of identity.
History
McTaggart's 1908 argument for the unreality of time framed the modern debate through the A-series and B-series. Prior developed tense logic for the A-theory. The persistence debate between endurantism and perdurantism crystallized in the late twentieth century with Lewis and Sider, while Parfit transformed work on personal identity.
Debates
- Does time pass?
- A-theorists hold that the flow of time and the privileged present are objective features of reality; B-theorists, often citing relativity, hold that passage is a feature of our experience, not of time itself.
Key figures
- J. M. E. McTaggart
- Arthur Prior
- David Lewis
- Theodore Sider
- Derek Parfit
- Sydney Shoemaker
Related topics
Seminal works
- mctaggart1908
- sider2001
- parfit1984
Frequently asked questions
- What is the difference between the A-theory and B-theory of time?
- The A-theory holds that there is an objective, moving present and that time really passes. The B-theory holds that all times are equally real and that temporal facts are exhausted by tenseless relations such as 'earlier than', with passage being merely apparent.