libterm.com Global supervenience refers to the philosophical concept where the properties of an entire system depend on the properties of its parts in a consistent and non-reducible manner. This principle is vital in metaphysics and philosophy of mind for understanding how higher-level phenomena relate to lower-level physical states. Explore the rest of the article to deepen your understanding of how global supervenience shapes debates in these fields.
Table of Comparison
| Aspect | Global Supervenience | Weak Supervenience |
|---|---|---|
| Definition | Dependence of global properties on the total distribution of lower-level properties across possible worlds. | Dependence of properties on lower-level properties within a single possible world. |
| Scope | Across all possible worlds. | Restricted to individual worlds. |
| Relation Type | Holistic, considering entire worlds. | Local, considering specific instances. |
| Application | Used in metaphysics and philosophy of mind to explain global property determination. | Common in semantics and composition where within-world constraints matter. |
| Key Feature | Identical lower-level distributions globally entail identical higher-level properties. | Identical lower-level properties within a world entail identical higher-level properties. |
| Philosophical Importance | Supports arguments for holistic property dependence and non-reducibility. | Supports context-dependent or world-relative interpretations. |
Introduction to Supervenience in Philosophy
Supervenience in philosophy describes a dependency relation where a set of properties A supervenes on another set B if no two entities can differ in A-properties without differing in B-properties. Global supervenience emphasizes this dependency at the level of entire possible worlds, meaning that if two worlds are identical in B-properties, they must be identical in A-properties. Weak supervenience restricts this dependence to individual objects or specific domains within a single world rather than across whole possible worlds.
Defining Global and Weak Supervenience
Global supervenience occurs when the properties of an entire set of objects depend on the collective properties of their parts, ensuring no difference in global properties without a difference in local properties across the whole domain. Weak supervenience requires that if two objects are indistinguishable in their local base properties at a given time, they must share the same local supervenient properties, but this dependence does not extend across all possible worlds or times. The key distinction lies in global supervenience applying to entire possible worlds or domains, while weak supervenience applies only within a single world or time frame.
Historical Background and Theoretical Context
Global supervenience emerged as a key concept in metaphysics during the late 20th century, particularly through the work of philosophers like Jaegwon Kim and David Lewis, to address holistic relationships between sets of properties across possible worlds. Weak supervenience, introduced earlier, focuses on a more restricted relation, where properties supervene within a single world, emphasizing local rather than global dependency conditions. The development of these notions reflects broader theoretical efforts to clarify how higher-level properties, such as mental or moral properties, depend systematically on lower-level physical properties within different metaphysical frameworks.
Key Features of Weak Supervenience
Weak supervenience asserts that if two possible worlds are identical with respect to a base set of properties, they must be identical with respect to a supervenient set of properties, but it only considers worlds within the same domain or class. Key features of weak supervenience include its restriction to a fixed domain, its applicability to variations in properties within that domain, and its inability to guarantee cross-domain or cross-possible-world dependence. Unlike global supervenience, which holds universally across all possible worlds and domains, weak supervenience is limited and context-dependent.
Essential Aspects of Global Supervenience
Global supervenience requires that any difference in the global distribution of non-supervenient properties corresponds to a difference in the distribution of supervenient properties across all possible worlds, establishing a strong holistic dependence. This contrasts with weak supervenience, which only demands this dependency within individual possible worlds, allowing for variation across different worlds. The essential aspect of global supervenience is its capacity to enforce a world-wide constraint ensuring that all possible variations in underlying properties are captured by variations in higher-level properties, reflecting a comprehensive metaphysical grounding.
Major Differences: Global vs. Weak Supervenience
Global supervenience requires that any change in the supervenient properties across possible worlds must correspond to a change in the subvenient properties across the entire worlds, ensuring holistic dependence. Weak supervenience, in contrast, only demands that within a single world, differences in supervenient properties imply differences in the subvenient properties, allowing for variation across different worlds. The major difference lies in their scope: global supervenience spans entire possible worlds collectively, while weak supervenience is restricted to individual world-level comparisons.
Philosophical Implications and Applications
Global supervenience asserts that any difference in the global physical state necessarily entails a difference in the global mental or moral state, emphasizing an all-encompassing dependency relation crucial for holistic interpretations in philosophy of mind and ethics. Weak supervenience restricts this relation to possibilities within a single possible world, allowing for variance across worlds and influencing modal metaphysics and the analysis of properties. Philosophical implications include debates on reductionism, emergence, and non-reductive physicalism, with applications in developing coherent theories of consciousness, moral realism, and the metaphysics of modality.
Criticisms and Challenges
Global supervenience faces criticism for its reliance on holistic conditions, making it difficult to apply in practical or scientific contexts due to the need for complete knowledge of an entire world or system. Weak supervenience is challenged by its limited scope, as it only requires local dependency, which can fail to account for broader, cross-world comparisons and may permit counterexamples where dependent properties vary despite base property similarities. Both concepts struggle with issues of metaphysical clarity and the potential for exceptions, raising debates about their adequacy in capturing the complexity of property interrelations.
Case Studies and Practical Examples
Global supervenience requires that any change in global properties entails a change in local properties across all possible worlds, often illustrated in ethics where moral attributes depend on the entire distribution of individual actions within a society. Weak supervenience, by contrast, holds that within a single possible world, no change in global properties can occur without a change in local properties, demonstrated in color perception studies where an object's overall color depends on its surface properties under specific viewing conditions. Case studies in metaphysics and philosophy of mind frequently employ these distinctions to examine the dependence of mental states on physical states, clarifying debates on property dependence and reductionism.
Conclusion: Comparing and Contrasting Global and Weak Supervenience
Global supervenience asserts that any change in subvenient properties across entire possible worlds necessitates a corresponding change in supervenient properties, emphasizing holistic dependency. Weak supervenience restricts this dependency to comparisons within the same possible world, allowing variations across different worlds without affecting supervenient properties. This distinction highlights global supervenience's stronger metaphysical commitment to cross-world uniformity, while weak supervenience offers a more localized and context-dependent relation.
Global supervenience Infographic
