For anyone interested in getting a deep exposure to current thinking about causation within the critical realist tradition, Ruth Groff's 2008 collection Revitalizing Causality: Realism about Causality in Philosophy and Social Science is a very good place to start. It begins with classic essays by Roy Wood Sellars from 1929 and 1943 -- long before the formulations of critical realism in Roy Bhaskar's writings -- and ends with essays by Robert Albritton and Howard Engelskirchen on the role of causal ideas in Marx's Capital. In between are articles by Christopher Norris, Charlotte Witt, Stephen Mumford, Anjan Chakravartty, Alexander Bird, and Rachel Cooper on various Aristotelian questions arising within the theory of causation, as well as articles by Douglas Porpora and Andrew Bennett on the applicability of causal realism to the social sciences.
Groff's introduction does a good job of setting the context for the volume. She defines the unifying thread of the volume as the underlying and somewhat independent efforts to make sense of a neo-Aristotelian understanding of causation that will work for contemporary science. And the emerging theory is a realist theory of causation.
That philosophers engaged in argument about the nature of dispositions, and social scientists trying to determine the causal properties of macro-level phenomena such as value, are working within and upon the same emerging neo-Aristotelian framework may not be readily apparent, given the normal configuration of conferences, journals, and disciplinary associations. Nonetheless it is so. (2)
Here are a few key themes and issues that readers will take away: causes are real; causal relations depend on real causal powers of active particulars; the theory of causation requires new (and old) thinking about metaphysics; things have essences; causal necessity is real; there are emergent causal powers.
Here is Roy Wood Sellars' definition of realism:
As a physical realist I believe in physical systems (ordinarily called things) which exist independently of our knowing them and which have specific characteristics. (13)
And Sellars argues that realism requires a different ontology from that associated with empiricism -- not "object with properties" but a "determinate object":
Now if this basic reality of a determinate object, a that-what, is once granted, we can reject at once the scheme which dominated representative realism of the Lockian type and animated Berkeley's dialectic. 'Support' and 'inhere in' and 'spread under' are clearly totally misleading metaphors for this basic unity. The determinate nature of an object is not something distinct in any fashion from the object. The object and its nature, or characteristics, are intrinsically one. (16)
A key question running through most of the contributions is the status of the idea of causal necessity. The authors share an anti-Humean point of view on causation -- the idea that all there is to causation is constant conjunction -- but they recognize that this creates an obligation to interpret the idea of causal necessity in a comprehensible way.
Harré and Madden offer their theory of natural necessity in "Conceptual and natural necessity", drawn from Causal Powers: Theory of Natural Necessity. They note an intriguing parallel between conceptual and natural necessity and they offer a specific interpretation of the evolution of scientific vocabulary that allows a closer parallel between the two kinds of necessity than either Kant or Quine would countenance:
We have argued that in the two contexts of natural necessity, the inherence of essential properties in a thing or substance and causal production, a posteriori discoveries about the natures of things and the means of causal production are in certain conditions reflected in the establishment of meaning relations between the corresponding predicates. (72)
In their very interesting treatment of the development of the scientific concept of copper, they find that:
There are thus a multiplicity of explications of the concept 'copper': as a red, easily worked metal; a mixture of sulphur, mercury and salt; a collection of atoms each sixty-three and a half times the weight of a hydrogen atom; and finally a collection of atoms each with a definite and identical internal structure. It is our view that these explications disclose substantially different meanings of the concept, limited by a core of identity in the nominal essence, and the changes so disclosed are the product of a posteriori discoveries as to the nature of copper. (75)
And it is the "essential" nature of copper that gives rise to its causal properties.
Another idea, linked to the first, that comes in for a fair amount of attention is the idea of a natural kind (or a social kind). This idea is deployed to support the first issue of natural necessity, in that it invokes the idea that things have essential natures that give rise to their causal properties. A natural kind is a group of things that share an essential nature, and these things can be counted on to display similar causal properties.
Brian Ellis's arguments for this perspective in his The Philosophy of Nature: A Guide to the New Essentialism are represented here.
A natural kind of process that is a display of a given dispositional property has a real essence. In the case of any simple causal process, this real essence will be a dispositional property, and the scientific problem will be to specify precisely what this property is. (90)
And, like Harré and Madden, Ellis regards the description of the essential properties of a natural thing to be the work of aposteriori investigation:
An attractive feature of this analysis is that it leaves dispositional properties to be identified and explicated rather than defined operationally. And the processes of explication is not philosophic, linguistic or lexicographic. It is a posteriori and scientific. (92)
Several other pieces are also noteworthy. Stephen Mumford further develops the ontology of powerful particulars in his contribution, "Powers, dispositions, properties or a causal realist manifesto", with a view that seems to me to be consistent with R. W. Sellars' insistence above on the primacy of the "determinate object". And Alexander Bird takes up the question of emergent properties and their possible causal roles. "Genuinely natural, causally efficacious higher level properties that are not identical nor reducible to lower level properties are emergent properties" (168). He focuses particularly on "evolved" properties, including particularly the functional characteristics of species.
One thing I admire about the volume is that it is focused on the philosophical and substantive issues, not points of doctrine within the literature of critical realism since Bhaskar's original formulations. Groff draws attention to this fact at the end of her introduction.
I have shaped the collection in this way because I believe that as interest in critical realism continues to grow internationally, the approach ought to be brought into closer contact with -- and ideally integrated into -- larger, directly relevant neo-Aristotelian currents within metaphysics and the philosophy of science. (8)
Readers will likely take issue with one or more of these premises; and the value of the volume is precisely that its contributors have made the issues clear enough to support fruitful debate.