Anomalous Monism

Core Idea

Donald Davidson's anomalous monism (1970) holds that mental events are identical with physical events (monism) but that mental event types cannot be systematically reduced to or correlated with physical event types (anomalism). Each mental event token is a physical event token, but there are no strict psychophysical laws connecting mental and physical descriptions. Mental descriptions are governed by norms of rationality (the principle of charity) rather than strict causal laws, making psychology 'anomalous' — it operates under different constitutive principles than physics. Davidson attempts to reconcile the causal efficacy of the mental with the autonomy of mental description, though Kim argues this leaves mental properties causally impotent.

How It's Best Learned

Read Davidson's 'Mental Events' (1970). The key is understanding why Davidson thinks mental/physical event identity is compatible with irreducibility of mental descriptions: identity is a relation between events (particulars), while reducibility concerns types or predicates. Then trace how Kim's exclusion argument targets Davidson's position specifically.

Common Misconceptions

• 'Anomalous' does not mean 'weird' or 'irregular'; it means that mental events, described under mental descriptions, do not fall under strict causal laws.
• Anomalous monism is not eliminativist: Davidson affirms the reality and causal efficacy of mental events — he just denies there are strict psychophysical bridge laws.

Explainer

From your study of physicalism and identity theory, you know that type identity theory (Smart, Place) held that mental types — pain, belief, desire — are identical to physical types: pain = C-fiber firing, for instance. This is a strongly reductive view: psychology, in principle, reduces to neuroscience. You also know that property dualism denies this reduction while accepting that mental properties depend on physical ones. Donald Davidson's anomalous monism occupies unusual ground: it is monist at the level of *tokens* (individual events) but irreducibly dualist at the level of *types* (properties and descriptions).

The position rests on three claims Davidson takes to be jointly non-negotiable. First, mental events can cause physical events: my belief that it's raining and my desire to stay dry can cause me to pick up an umbrella. Second, causation is backed by strict laws: when event A causes event B, there is some strict law under which they fall. Third, there are no strict psychophysical laws: there is no systematic mapping of mental types onto physical types that constitutes a genuine bridge law. The first two claims are broadly accepted; the third requires argument. Davidson's reasoning is that mental descriptions are governed by normative standards — rationality, coherence, consistency — that have no analog in physical description. To interpret a person's mental states, you must make them rational; you cannot interpret them as a mere physical mechanism. Mental and physical descriptions are *constitutively different* in kind, not just coincidentally uncorrelated.

These three claims are in tension: if causation requires strict laws, and there are no strict psychophysical laws, how can the mental cause anything? Davidson's resolution is a token-token identity: each individual mental event *token* is identical to some physical event token, and it is *under its physical description* that the event falls under a strict causal law. My belief-token is identical to some brain-state-token, and *qua* brain-state it enters into physical causal relations governed by neuroscientific or physical laws. Mental event causation is real, but the causal work is done by the physical description of the event.

The legacy of anomalous monism is largely shaped by Jaegwon Kim's critique. If mental properties — the properties that make an event a belief rather than just a neural firing — do no independent causal work, then they are epiphenomenal: present, but causally idle. Kim's exclusion argument presses this: given that physical causes are sufficient for physical effects, what causal role is left for mental properties? Davidson insists that mental event *tokens* are causally efficacious, but Kim argues that without type-level connections, the mental properties themselves are doing nothing. This is the central unresolved tension: anomalous monism saves mental causation at the level of events while appearing to lose it at the level of properties — which is precisely where the explanatory interest lies.