Peter Fazekas (University of Antwerp)
The mechanistic framework traditionally comes bundled with a levelled view of reality, where different entities forming part-whole relations reside at lower and higher levels. Here it is argued that contrary to the standard understanding and the claims of its own proponents, the core commitments of the mechanistic framework are incompatible with the levelled view. An alternative flat view is developed, according to which wholes do not belong to levels higher than the constituent parts of the underlying mechanisms, but rather are to be found as modules embedded in the very same complex of interacting units. Modules are structurally and functionally stable configurations of the interacting units composing them. Modules are encapsulated either in a direct physical way by a boundary that separates them from their environment, or functionally by the specific organisation of the interaction network of their units (e.g., causal feedback loops). Physical and functional encapsulation constrain internal operations, cut off some internal-external interactions, and screen off inner organisation and activities. Due to the cutting-off effect of encapsulation, the interacting units of a module are, to a certain degree, causally detached from their environment: some of the causal paths via which the units could normally (in separation) be influenced become either unavailable (due to the shielding effect of physical boundaries) or ineffective (due to the stabilising effect of feedback loops). Some units, however, still retain their causal links with the environment providing inputs and outputs for the organised activity of the cluster of units, and henceforth for the module itself. Modules, thus, are not epiphenomenal. The input of a module is the input of its input units, and the output of a module is the output of its output units. Via the causal links of their input and output units, modules are causally embedded in the same level of causal interactions as their component units. Since whole modules can be influenced by and can influence their environment only via their input and output units, their inner organisation is screened off: from the ‘outside’ modules function as individual units. Therefore, alternating between a module and a unit view is only a change in perspective and does not require untangling possibly complex relations between distinct entities residing at different levels. The mechanistic programme consists in turning units into modules, i.e., ‘blowing up’ the unit under scrutiny to uncover its internal structure, and accounting for its behaviour in terms of the organisation and activities of the units found ‘inside’. The flat view, thus, claims that mechanistic characterisations of different ‘levels’ are to be understood as different descriptions providing different levels of detail with regard to a set of interacting units with complex embedded structure. It sets the mechanistic programme free of problematic metaphysical consequences, sheds new light on how entities that traditionally were seen as belonging to different levels are able to interact with each other, and clarifies how the idea of mutual manipulability — that has recently been severely critcised — could work within the mechanistic framework.
