Assemblages: Downward Causation and Upwards Dependence

According to Manuel Delanda an assemblage such as an organism or an economic system is an emergent but decomposable whole. Unlike a totality, an assemblage’s parts can follow independent careers:

Pulling out a live animal’s heart will surely kill it but the heart itself can be implanted into another animal and resume its regular function. (Delanda 2011, 184).

Nonetheless, the emergent properties of a given assemblage W depend ‘on the actual exercise of the capacities of its parts’ (p1, p2… pn).

If this dependency is construed as supervenience then Delanda seems to confront the ‘causal exclusion problem’ for emergent properties by their basal conditions anatomized by Kim. Suppose facts about W’s emergent properties supervene on a basal fact P about p1, p2… pn and that a given emergent property M of W at time t is causally sufficient to bring about another emergent property M* by bringing about a basal condition P* (some state of p1, p2… pn belonging to the supervenience base of M*). Given the upwards dependence constituted by the supervenience relation (the fact that having P suffices for having M but not vice versa) it seems counter-intuitive to claim that the basal condition for M, P (the aforementioned exercise of the micro-capacities), could not cause P* on its own. So responsibility for inter-level causation between emergent properties M, M* can be entirely devolved onto their basal conditions ‘making the emergent property M otiose and dispensable as a cause of P*’ (Kim 2006: 558).

The causal exclusion argument clearly threatens the flat ontological assumption that assemblages have causal autonomy.

There are strategies by which one might hope to de-fang the causal exclusion argument. As Andreas Hüttemann points out supervenience may run symmetrically from properties higher to lower scales as well as from lower to higher (Hüttemann 2004: 71). No change in emergent properties without changes in a given class of basal properties (upwards supervenience) is compatible with no changes in basal properties without changes in a given class of emergent properties (downwards supervenience). If asymmetric supervenience is the assumption motivating causal exclusion then symmetric supervenience undermines a key premise in the argument.[i]

However, it is not clear that Delanda would want to commit himself generally to symmetrical supervenience, if only because he claims that emergent properties can be stable against significant perturbations at the micro-level. Science, he claims, is only possible on the condition that we can ‘chunk’ stabilities at a given level without modeling all the way down (2011: 14). Folk psychology does not require folk neuroscience; knowledge of classical genetics does not require molecular genetics.

A more congenial avoidance strategy could be furnished by an account of how wholes exercise ‘top down’ influence on the manifestation of capacities. While Delanda has not, to my knowledge, discussed supervenience, he is explicitly committed to the existence of top-down as well as bottom-up causality – a position he explicates in terms of the distinction between properties and capacities (See, for example, Delanda 2010b, 68-70). The properties of a thing are necessarily actualized but the actualization of capacities is context-sensitive (Delanda 2011: 4). Delanda regards the actualization of capacities not as a ‘state’ but an event or interaction since it includes the affecting of one thing and the being-affected of another (Ibid; see also Delanda 2010a: 385).

For example, Chapter Eleven of Philosophy and Simulation considers the problem space for the emergence of archaic states from simpler chiefdoms in which wealth and status differences disseminated more fluidly. One explanation for the more stratified forms found in complex cheifdoms or proto-states is that the relaxation of incest prohibitions on marrying close relatives would have allowed persistent concentrations of wealth and status – an explanation with prima facie support from multi-agent computer simulation (Delanda 2011: 172). So while a given accretion of agricultural wealth, say, has capacities for distributions between lineages or within lineages, there are critical parameters determining which is actualized.

Chapter Seven ‘Neural Nets and Mammalian’ memory considers the conditions for the emergence of the capacity for episodic memory on the basis of simpler networks that lacked the capacity to present processes or histories. The capacity for nervous systems to synthesize the manifold of successive waves of stimuli can be modelled using so-called ‘recurrent neural networks’ which add feedback from their hidden layers to the input to be received on the next round of stimulation. The result is that net can be trained to recognize temporal patterns such as bounding balls or chord sequences (Ibid. 103-4). Thus any given layer of neurons has the capacity to represent temporal regularities, but can manifest it only if ‘plugged’ into a network with the right topology.

So parameterized constraints (like incest prohibitions) or structural properties (like network topology) can, it seems, downwardly activate manifestations of component-capacities, explaining the dependence of component behaviour on the assemblages to which they belong. Is this enough to grant ontological autonomy?

Well, this is surely a debatable point. ‘Downward influence’ of this kind is also exhibited in very simple cellular automata like John Conway’s game of life as much as in real systems (Delanda 2011: Chapter Two). The Game of Life is a two dimensional array of cells, each of which can be ‘Alive’ (On) or ‘Dead’ (Off) at a given time step. The states of the cells are determined by three simple rules:

1) A dead cell with exactly three live neighbors becomes alive on the next time step.

2) A live cell with two or three live neighbors stays alive.

3) In all other cases a cell dies or remains dead.

These rules pass for fundamental physics in the Life World. Yet computer simulations show that patterns exhibiting complex, often unpredictable dynamical regularities can ‘emerge’ from these though all realized in arrangements determined by the three rules (Bedau 1997).  In all cases these involve higher-level structures constraining the capacities of individual cells, yet it is not clear that these should be treated as ontologically distinct from mere aggregates. Nor is it obvious that true ontological novelty can occur in a world where every thing is an aggregation of recurrent constituents determined by invariant rules.

 

References

Delanda, M. (2004), Intensive Science and Virtual Philosophy. London: Continuum.

Delanda, M. (2006), A New Philosophy of Society: Assemblage Theory and Social Complexity. London: Continuum.

Delanda, M (2010),’Emergence, Causality and Realism’, in Levi Bryant, Nick Srnicek and Graham Harman (eds) The Speculative Turn: Continental Materialism and Realism (Melbourne: Re.press).

Delanda, Manuel (2011), Philosophy and Simulation: The Emergence of Synthetic Reason, London: Continuum, 226 pp.

Hüttemann, Andreas (2004), What’s Wrong with Microphysicalism? London: Routledge.

Kim, Jagewon (2006), ‘Emergence: Core Ideas and Issues’, Synthese 151(3), pp. 547-559.

 

 

 

 

 

 

[i] There may, of course, be ways of casting the causal exclusion argument that do not hinge of asymmetric supervenience.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s