libterm.com Weak supervenience is a philosophical concept describing a relationship where changes in higher-level properties depend on changes in lower-level properties, but the dependency need not be strict or uniform across all possible cases. This notion allows for variability within categories, meaning that two systems can share all lower-level properties without necessarily sharing higher-level features. Explore the rest of the article to understand how weak supervenience contrasts with strong supervenience and its implications for metaphysics and philosophy of mind.
Table of Comparison
| Aspect | Weak Supervenience | Strong Supervenience |
|---|---|---|
| Definition | Properties supervene only within a single possible world. | Properties supervene across all possible worlds. |
| Scope | Intra-world dependency. | Inter-world dependency. |
| Modal Strength | Weaker modal claim. | Stronger modal claim. |
| Example | Two objects in the same world cannot differ in moral properties without differing in physical properties. | Any two objects, in any possible world, cannot differ in moral properties without differing in physical properties. |
| Philosophical Use | Used to analyze local property dependence. | Used for global property dependence and necessity. |
Introduction to Supervenience
Supervenience is a fundamental philosophical concept describing a dependency relationship where a set of properties A supervenes on another set of properties B if no change in A-properties occurs without a change in B-properties. Weak supervenience holds this dependency only within a single possible world, meaning A-properties cannot differ without B-properties differing in that world. Strong supervenience extends this across all possible worlds, ensuring that if two entities are identical in their B-properties, they must also be identical in their A-properties, reflecting a more robust form of dependency.
Defining Weak Supervenience
Weak supervenience is defined as a relationship between two sets of properties where any change in the supervenient properties requires a change in the subvenient properties, but not necessarily the converse across all possible worlds. This contrasts with strong supervenience, which demands that the supervenient properties depend on subvenient properties in every possible world, ensuring a more rigid dependence. The distinction is crucial in metaphysics and philosophy of mind for understanding property dependence and ontological commitments.
Defining Strong Supervenience
Strong supervenience defines a strict dependence relation where any change in higher-level properties necessitates a change in underlying lower-level properties across all possible worlds, ensuring a consistent and universal dependency. Unlike weak supervenience, which applies only within a single world, strong supervenience mandates this correlation hold globally and necessarily. This concept is pivotal in metaphysics and philosophy of mind, particularly in debates about physicalism and mental states.
Key Differences Between Weak and Strong Supervenience
Weak supervenience requires that any change in supervenient properties corresponds to a change in subvenient properties within a given domain or world, while strong supervenience mandates that this correspondence holds across all possible worlds. Strong supervenience implies a global dependence of higher-level properties on lower-level bases, ensuring no counterexamples exist in any possible world, whereas weak supervenience allows for exceptions outside the actual world. The key difference lies in the modal scope: weak supervenience is world-relative, and strong supervenience is world-independent, providing a more robust metaphysical connection.
Philosophical Importance of Supervenience
Weak supervenience asserts that differences in higher-level properties correspond to differences in lower-level properties within the same possible world, while strong supervenience extends this across all possible worlds, emphasizing a more robust dependency relation. The philosophical importance of supervenience lies in its role in explicating the relationship between mental states and physical states, grounding debates in philosophy of mind, metaphysics, and ethics concerning reducibility and emergent phenomena. Understanding these distinctions aids in clarifying concepts such as physicalism, non-reductive materialism, and the nature of property dependence.
Weak Supervenience: Implications in Philosophy of Mind
Weak supervenience describes a relationship where mental properties depend on physical properties within individual possible worlds but do not guarantee this dependency across all possible worlds. This notion supports non-reductive physicalism in the philosophy of mind by allowing mental states to be causally efficacious without being strictly reducible to physical states. Emphasizing weak supervenience highlights challenges in explaining mental phenomena solely through physical bases, underscoring the complexity of mind-body interactions.
Strong Supervenience: Applications in Metaphysics
Strong supervenience asserts that any change in the supervenient properties necessarily involves a change in the subvenient properties across all possible worlds, providing a rigorous framework for metaphysical dependence. In metaphysics, strong supervenience is applied to analyze the relationship between mental states and physical states, ensuring that identical physical states guarantee identical mental states universally. This concept is crucial in debates on physicalism and the mind-body problem, as it underpins arguments for the non-reducibility of mental phenomena while maintaining a consistent dependence on physical bases.
Examples Illustrating Weak and Strong Supervenience
Weak supervenience occurs when mental states depend on physical states within a single possible world, such as two individuals having identical brain states but different mental experiences not across worlds but within the same world. Strong supervenience implies that mental states depend on physical states across all possible worlds, exemplified by a scenario where any two physically identical beings in any possible world must have identical mental states. For example, weak supervenience allows that in one world, twins might have differing mental attitudes despite sharing identical brain states, while strong supervenience demands that identical brain states guarantee identical mental states universally, across all conceivable worlds.
Criticisms and Challenges to Supervenience Theories
Weak supervenience faces criticism for its inability to account for modal robustness, as it only guarantees dependence within a fixed domain of possible worlds, leading to challenges in explaining essential property relations across broader metaphysical contexts. Strong supervenience is often challenged for its demanding nature, requiring universal dependency that struggles with issues like multiple realizability and the apparent independence of mental states from physical substrates in some philosophical accounts. Both forms encounter difficulties in addressing the explanatory gap and ontological clarity, raising questions about their adequacy in capturing the complexity of emergent properties and inter-level relations.
Conclusion: Evaluating Weak vs Strong Supervenience
Weak supervenience allows for variations in properties across possible worlds without strict property correlation, while strong supervenience requires a consistent and strict dependency of higher-level properties on lower-level properties across all possible worlds. Evaluating these concepts highlights that strong supervenience offers a more robust framework for establishing necessary relations in metaphysics and philosophy of mind, ensuring no variation in supervening properties without a change in subvening properties. Weak supervenience, though more flexible, lacks the rigorous explanatory power needed for definitive philosophical analyses of property dependence and ontological structure.
Weak supervenience Infographic
