The Kantian doctrine of freedom turns on the idea that the acting agent is neither fully part of nature nor fully outside of nature. Nature, on this doctrine, is a totally causal system governed by strict laws of necessity. The acting agent is self-governed (according to Kant) by reason and bound by the moral law, and it would make no sense for the agent to be bound by the moral law if he wasn’t free to obey the moral law. Freedom here is a condition for the possibility of duty – the agent must be free from the causal/necessitarian order of nature, in other words. Whether or not Kant’s doctrine as a whole can withstand scrutiny is a matter of debate, but surely his fundamental insight is worth reflecting on: the possibility of free agency requires that the free agent not be subject to strict causal laws. Jaegwon Kim, in Psychophisical Laws, notes that Donald Davidson’s theory of anomalous monism was developed out of roughly Kantian concerns – Davidson accepts a picture of the physical world that is fully and causally determined, but wants to retain a place for mental autonomy and the possibility of free agency.
Davidson’s doctrine of anomalous monism goes some way towards fleshing out a response to this Kantian insight from the perspective of analytic philosophy of mind. Davidson essentially argues that the concept of the mental is characterized in such a way (Davidson here relies on intentionality being a key essential feature. Propositional attitudes exemplify, for Davidson, mental states) that if it were tied too closely to the physical it would, in effect, cease to be mental:
The mental realm is characterized by certain essential features which would be seriously compromised if there were connections as strong as laws, with their modal and subjunctive force, linking it with the physical realm, which has its own distinctive essential features incompatible with the mental. These features of the mental are essential in that they are constitutive or definitive of the system of mental concepts; the mental realm cannot sustain their loss and still retain its identity as a mental system. (Jaegwon Kim Psychophiscal Laws, in Supervenience and the Mind, pp. 200-201)
This forms the backbone of Davidson’s argument. A key feature of intentionality here is a holistic conception of rationality, which is a condition for the possibility of ascribing mental states to an agent. Without this rationality, we have no real grounds to attribute a mental state to an agent, because without this rationality is what it is to be an agent:
The mental is holistic in that the attribution of any single mental state to a person is strongly constrained by the requirements that the totaly system attributed to him of beliefs, desires, fears, hopes, and all the rest be maximally coherent and rational. This coherence or rationality maximization condition, on Davidson’s view, is an essential feature of the intentional; without it we cannot make sense of ascription of contentful mental states. (p. 203)
Why, exactly, can there not be nomological connections between the mental as conceived here and the physical? We have seen that the mental is characterized rationality and intentionality; for Davidson the physical is characterized by its lack of these very properties:
Any effort at increasing the accuracy and power of a theory of behavior forces us to bring more and more of the whole system of the agent’s beliefs and motives directly into account. But in inferring from this system from the evidence, we necessarily impose conditions of coherence, rationality and consistency. These conditions have no echo in physical theory, which is why we can look for no more than rough correlations between psychological and physical phenomena. (Davidson, Mental Events, emphasis mine)
These two realms – the mental and the physical – are thus fundamentally characterized by features that cannot be linked in a nomological way without losing their identity as mental or physical phenomena. For Davidson, in effect, such laws binding the two realms together would ‘transmit’ features of each realm to the other, which is incoherent. This, in a nutshell, is his psychophysical anomalism: there are no laws that bind together mental and physical phenomena. There simply cannot be. This is a core plank in his argument for anomalous monism. The second core plank is Davidsons’s psychological anomalism. We have seen that there and cannot be laws connecting the mental and the physical, and Davidson is rejecting the idea that there are pure psychological laws that can predict mental events, on the basis that the mental realm does not form a closed system to which laws can apply:
It is not plausible that mental concepts alone can provide [a comprehensive framework for the description and law-based prediction and explanation of events] simply because the mental does not…constitute a closed system. Too much happens to affect the mental that is not itself a systematic part of the mental. But if we combine this observation with the conclusion that no psychophysical statement is, or can be built into, a strict law, we have the principle of the Anomalism of the Mental: there are no strict laws on the basis of which we can predict and explain mental phenomena. (Davidson, Mental Events, quoted in Kim, Supervenience and Mind, p. 209-210)
Kim provides a lucid overview of Davidson’s movement:
If mental phenomena can be nomologically explained and predicted, then the required laws would have to be either psycophysical or purely psychological. Psychophysical Anomalism says laws of the first kind are not there; Psychological Anomalism says laws of the second kind are not there either. So there are no laws to explain and predict mental phenomena, and this is precisely Anomalism of the Mental. (p. 210)
At this point, Kim picks up on a very interesting but slightly subterranean theme in Davidson’s Mental Events: Davidson is, contra inital appearances, looking for mental law(s), since he speaks of a ‘viable theory’ of propositional attitudes, and, as Kim notes, ‘what is a theory made up of, if not laws?’ (p. 211) But haven’t we just seen that Davidson rejects just such talk of laws in relation to the mental? Yes, if by laws we mean purely predictive laws – Kim argues, however, that normative rather than predictive laws, are entirely appropriate to Davidson’s project:
I suggest the line of reconciliation: on Davidson’s account, the mental can, and does, have its own ‘laws’; for example, ‘laws’ of rational decision making . The crucial point, though, is that there are normative rather than predictive laws. When Psychophysical Anomalism and Psychological Anomalism deny the existence of laws about the mental, the meaning of ‘law’ involved is one that is appropriate to physical theory, namely the concept of law that permits the formulation of nomological predictions and explanations on the basis of precisely characterized and empirically identifiable initial and boundary conditions. It may be recalled that the Anomalism of the Mental only denies the existence of (in Davidson’s own words) ‘strict laws on the basis of which behavior can be explained and predicted’. Thus, the existence of nonpredictive normative laws or principles is consistent with the Anomalism of the Mental and Psychological Anomalism. (p. 211)
The mind is thus secured in its status as an autonomous realm, and free human agency is also secured, since the realm of physical, necessitarian laws is one to which the realm of the mental, and thus the realm of free human agency, stands outside. The realm of rationality that is the condition of the possibility of our concept of ourselves as free, acting and norm-following agents cannot be conceived of in terms of the realm of physical theory and physical law without our losing our grip on the very idea of ourselves.