Canadian Journal of Philosophy 36.2 (2006) 281-305
[Access article in PDF]
Kant, Causation, and Freedom
Boulder, CO 80309-0232
Now although there is an incalculable gulf fixed between the domain of the concept of nature, as the sensible, and the domain of the concept of freedom, as the supersensible ... yet the latter should have an influence on the former, namely the concept of freedom should make the end that is imposed by its laws real in the sensible world; and nature must consequently also be able to be conceived in such a way that the lawfulness of its form is at least in agreement with the possibility of the ends that are to be realized in it in accordance with the laws of freedom.
Quine notoriously distinguished between those interested in the history of philosophy, and those interested in philosophy. From a contemporary standpoint this is somewhat ironic, because it is clear that Quine himself should have paid more attention to the history of the analytic-synthetic distinction.2 This points up the important metaphilosophical fact that one of the ways in which the history of philosophy can actually drive the rest of philosophy is by historically re-examining and re-working seemingly settled topics, and showing us that philosophically things really were not the way we have uncritically assumed them to be. That in turn can lead us to question unargued assumptions, and even change our view of the conceptual landscape and the relevant possibilities in logical space. Eric Watkins's Kant and the Metaphysics of Causality (henceforth KMC) is a particularly beautiful example of this regressive strategy for moving forward philosophically.
The trick, of course, is to pick your targets carefully: they should be central to the mainstream of contemporary philosophy, not marginal. Watkins has certainly done that. The target he has chosen is the problem of causation. His three-part aim is, first, to embed Kant's theory of causation in its 18th century pre-Critical and especially Leibnizian setting; second, to argue that Kant's Critical theory of causation is not in fact a reply to Hume, and that Kant's metaphysics of causation depends as much on the Third Analogy of Experience and the Third Antinomy of Pure Reason as it does on the Second Analogy; and third, that reconsidering Kant's Critical metaphysics of causation from a pre-Critical and rationalist point of view can contribute to a serious reconsideration [End Page 282] of the theory of agent causation in the contemporary debate about free will.
II Kant and the Problem of Causation
The concept of causation has two faces. The first face is turned towards the dynamics of physical nature, and the second face is turned towards the dynamics of intentional action. Nevertheless since all the intentional agents we are directly acquainted with are also animals and thus living organisms, it seems reasonable to hold that the dynamics of physical nature and the dynamics of intentional action are ultimately the same. This remains true despite a common methodological tendency after 1950 to segregate their metaphysics by shunting physical causation and intentional action onto the specialist spurs of the philosophy of physics and action theory. But philosophical problems, like runaway trains, have a way of getting off the tracks neatly laid for them and smashing into one another — and in this case, they collide precisely at the point where the fundamental biology of human intentional agents meets the fundamental physics of inert matter.
So what is the problem of causation? Since at least the 17th century, physical nature has been thought to operate according to universal strict mechanical laws, whether deterministic or statistical. At the same time intentional agency has been held to operate according to psychological and moral principles that require freedom of the will. In turn, it seems that given an actual psychological or behavioral event E, freedom of the will with respect to E...