tags: - colorclass/david marx’s theory of mind ---see also: - Theories and Philosophies of Downward and Upward Causation - Philosophy of Causality - Philosophy of Science - Philosophy of Mind - Causal Exclusion Argument
The principle of causal closure is a foundational concept in the philosophy of science, particularly in the philosophy of mind and metaphysics. It asserts that physical events are entirely determined by other physical events, leaving no room for non-physical causes to influence the physical world. This principle has significant implications for debates about the nature of causation, the mind-body problem, and the possibility of downward causation.
Definition
Causal Closure of the Physical: Every physical event has a sufficient physical cause. This principle can be formally stated as:
Implications
1. Determinism: The principle of causal closure supports a deterministic view of the physical world, where every physical event is caused by previous physical events in accordance with the laws of nature.
2. Exclusion of Non-Physical Causes: Non-physical entities, such as mental states or supernatural forces, cannot cause physical events if causal closure holds true. This has implications for dualism and theories that posit non-physical substances.
3. Scientific Explanation: The principle underpins the scientific method, which seeks to explain phenomena through physical causes and empirical investigation.
Relation to Upward and Downward Causation
Upward Causation
Upward causation aligns well with the principle of causal closure. In upward causation, higher-level properties and behaviors emerge from the interactions of lower-level physical components. Since these interactions are physical in nature, they do not violate causal closure.
Example: In biology, the functioning of an organism (higher-level property) is explained by the interactions of its cells and biochemical processes (lower-level physical events).
Downward Causation
Downward causation poses a challenge to the principle of causal closure because it suggests that higher-level properties can influence the behavior of lower-level physical components. If these higher-level properties are not reducible to physical events, it would imply that non-physical causes can affect the physical world, seemingly violating causal closure.
Example: In psychology, the mental state of stress (a higher-level property) influencing physiological responses (lower-level physical events) raises questions about whether the mental state is fully reducible to physical brain states or if it introduces a non-physical cause.
Philosophical Debates
1. Reductionism vs. Emergentism: - Reductionism: Advocates argue that all higher-level phenomena can be fully explained by physical processes, thus maintaining causal closure. - Emergentism: Proponents assert that higher-level properties emerge from but are not reducible to lower-level physical processes, challenging the strict interpretation of causal closure.
2. Non-Reductive Physicalism: - This view attempts to reconcile causal closure with the existence of higher-level properties. It posits that while mental states are physical, they are not reducible to simpler physical processes, yet they do not introduce new causal powers beyond the physical realm.
3. Epiphenomenalism: - A response to the challenge of downward causation, suggesting that higher-level properties (like mental states) are by-products of physical processes with no causal efficacy of their own, thus preserving causal closure.
Addressing Downward Causation within Causal Closure
1. Supervenience: - Definition: Higher-level properties supervene on lower-level physical states, meaning any change in the higher-level property necessitates a change in the lower-level state. - Implication: This allows higher-level properties to influence lower-level processes indirectly without violating causal closure, as the causal power remains within the physical domain.
2. Contextual Emergence: - Definition: Higher-level properties emerge from complex interactions of lower-level components and can exert causal influence within specific contexts defined by these interactions. - Implication: Contextual emergence suggests a form of downward causation that does not breach causal closure because the emergent properties are still grounded in the physical interactions of their components.
Summary
The principle of causal closure maintains that physical events are solely caused by other physical events, forming the basis for a deterministic and scientifically explainable universe. While upward causation fits comfortably within this framework, downward causation challenges it by suggesting that higher-level properties can influence lower-level physical events. Philosophical responses to this challenge include non-reductive physicalism, supervenience, and contextual emergence, which seek to preserve causal closure while acknowledging the complexity of emergent phenomena.