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A: 2pm Aaron Sloman Computer Science, University of Birmingham http://www.cs.bham.ac.uk/~axs Welcome, introduce participants, Introduce workshop: Present some of the "standard" Philosophical background expanded by Computational causation (e.g. causation in virtual machines composed of multiple asynchronously interacting virtual machines) Mathematical causation (e.g. moving a vertex of a planar triangle further from the opposite side causes the area to be increased, adding three marbles to a box containing five marbles causes the number of marbles to go up to eight, changing the curvature of a line causes infinitely many distances between parts of the line to change. B: 2:25-2:35 Questions discussion and clarification, mainly for the benefit of non-philosophers present. Objections/counter proposals postponed until after the following talks. D: Approx 2:35 Andrea Raimondi, Philosophy University of Nottingham http://about.me/Raimondiand Functional Dispositionalism Abstract: I work specifically on causal dispositionalism and functions, but will try to explain the metaphysics of causal powers, as background. 1. Dispositional Properties According to dispositionalism, causation is produced by the exercise of causal powers. The reason why dispositional properties are often called powers is to highlight their causal role. Dispositions inhere in the object of dispositional ascription. The causal in causal powers is the fact that their exercise is productive of the behaviour of things. Dispositions are not mere potentialities. Their manifestations do not depend on the presence of an active stimulus. To say that something is soluble is not to think that the property is instantiated only when the dissolving occurs (Mumford 1998). Dispositions are active, but they produce the effect by composing together with other dispositions. Causation as mutual manifestation partnership explains the effect as the change in powers when they team up. This starts a causal process that is diachronical, with which we can interfere and that have as effect a modification of the causal scenario. 2. Causal production The exercise of dispositions represents the causal production. For dispositionalism individual has their own causal powers and any effects exhibited are the manifestation of those powers. But objects possess dispositional properties even if those are not manifested. To say that dispositional property is a property that can exist unmanifested means that it points to objects' hidden potentials. A dispositional theory of causation sees discovery in the sciences as the exploitation of causal powers and achievements in technology as the ability to use objects' hidden dispositional properties to build systems specifically designed to support a constrained set of possibility. The role "powers" remark is that dispositional properties are actual causal properties that support object's potentialities. Causation as the passing around of powers depicts hidden potential as a disposition for the instantiation of another possible causal property. That which is soluble has the potential to become dissolved (Mumford 2009). Causation explains the activity of individual objects in virtue of their dispositional properties. Most of the complex biological interactions that dispositionalism claims to explain involve causal interaction. a) Not all the causal interactions are also functional. Then how a functional account of dispositions looks like? 3. Dispositionality as selection function The idea of selection function is meant to explain that when powers are exercised a subset of realm of possibilities is selected, favouring some among others. Change in dispositional properties is explained in terms of selection from a range of natural possibility (Mumford&Anjum 2011). Powers exercise provides the object with abilities to interact causally with the world, linking set of possible changes. The modal space available to the object is marked by the set of possible causal link between natural possibilities (Sloman 1996). Dispositional ascription allows causal explanation of behaviour of natural things. Since dispositionality selects natural possibility, not logical one, when powers are exercised we often know what to expect. But dispositionality acts between pure contingency and pure necessity. A disposition only tends toward its manifestation, but not necessitate the effect. We make sense of ascribing a dispositional property to an object even without necessitating the manifestation. 3.1 Compositional pluralism and directenss The same disposition can manifest differently in respect to the presence or absence of other powers at work. Compositional pluralism is the claim that there are pluralities of way in which powers can compose to produce an effect. When they team up they alter each other contribution to the causal outcome (Mumford&Anjum 2011). That a vase is fragile means there are possible ways in which the vase can be damaged: it can be struck by a hammer, pushed on the ground and smashed against the wall. There are also possible ways in which the vase can tend to break: it can break in piece, or tiny fragment, or burned to dust by a laser. Also a piece of metal could be fragile. However for the fragility of metal to manifest requires that other causal powers are in place. For instance, diminish the temperature of the object beyond a certain threshold and it will become as fragile as a vase. Dispositionality explains objects' modal facts that are effects of the powers control over potentialities. Powers act as a whole, at different level of reality. A kiss may cause embarrassing, as well as energy transfer between bodies. A cube of sugar can dispose toward dissolving in water, as well as sweetening the solution. b) Which one of this directness can be considered functional? 3.2 Getting functional Functional Dispositionalism assumes that things in nature generate, maintain and develop their own modal space and powers are causal in that they constrain possible change as causation occurs. Objects' dispositions depends on what natural possibilities are at hand and which outcome is brought about depends of which functional role can be instantiated. It is not obvious what it is for a disposition to be a function. A common assumption of dispositional ascription and functional ascription is that both endorse a function/accident distinction. Within this distinction the sweeten solution is an accidental effect of the functional ascription of the solubility (Wright 1976). Dispositional and functional are ascription that are always relative to a choice of explanandum (Wright 1973). c) Then, Is the claim that dispositional ascriptions are functional ascriptions informative? When we ascribe a disposition we are giving a functional characterization of the property, according to what potentiality support in different causal context. For something to be elastic means to have a dispositional properties that cause its stretch when pulled. We functionally characterize this disposition in terms of elasticity. Dispositional ascriptions are explanatory when they indicate what potency is present in the object of ascription. Functional characterization of this property does not exclude that same disposition can manifests other effects accidentally. Dispositionality as selection function causes possible changes in powers composition. To ascribe a disposition is to say something about what the objects can do, its modal space, not how it organize it. To say that A and B mutually manifest C is not to say how A and B compose C. If an object must exhibit a function it is because an object has the ability to do that. And to have ability is to have a disposition. Nonetheless a dispositional ascription just specifies that a causal contribution have a functional role, not how the contribution is integrated when other powers at work realize the function. Dispositionalist claim is informative in that suggest that dispositions are particular kind of functions (Mumford 1998). 4. Dispositionality and Complexity d) The realization of a function requires more than dispositional ascription. The modality of the system is represented as a selection function that acts on various dispositions whose manifestations work toward a common end-state. It is because disposition is a particular kind of function that we can admit the production of non-functional changes. For instance, the appearance of an adaptive trait in an organism is strongly coupled with the manifestation of non-adaptive trait. However those traits might reveal themselves functional during organism development (Nagel 1979). For powers to instantiate a function they must be organized appropriately. Is only when causal powers of many components are brought together in the right arrangement that hidden potentialities are supported, e.g. a bridge. Not all causal inputs are for a selection function can be considered fixed. When we pull ends of a climbing rope apart that could be different pathway to end-state. There could be knots forming that affect how the rope can be pulled. Its wetness can affect how the rope curls. A wire disposes to conduct electricity. But cooling down a piece of metal and same dispositions manifest superconductivity, together with the ability to store energy. With appropriate causal factor it can dispose toward making light. Where processes develops different constrain of possibility might emerge and affect the paths to the end-state. Those constrain are better understood as changes in complexity, affecting the way dispositions can compose together. In complex system functions always involve dynamically varying causal inputs that are selected toward a casual output, each of those modulates each other effect. The ways component are organized have effects upon the selection function, causing a change in complexity, both compositional and dynamical. Functions in systems are involved with possible interactions that change possibility between parts. We can join two wires in parallel and their voltage is constrained to be the same. When in series, the same happen in current. In both cases, the disposition ascribed to the system could not be reduce to the sum of the powers of the components. Two wires coupled in a diode compose a complex object whose functional characterization cannot be reduced to the sum of functional characterization of component properties. Functional dispositionalism can accept physicalism without imply reductionism since powers act at different levels of complexity. 4.1 Adaptive Emergence e) Powers exercise regulates the selection of naturally possible outcome in respect to interference in causal ecosystem in which the system behaves. Functional systems are responsive to causal ecosystem in which they behave. A functional account of dispositions can help investigate emergent abilities of biological systems in terms of adaptive response to environmental influence. Organization only disposes toward the end-state since systems behaviour is brought about by different dispositions working together. Dispositional ascription instantiate more than one functional role concurrently. The adapting feature of powers composition can represent a step toward the explanation of emergent change in complexity: evolved complexity (Mitchell 2003). This complex feature of biological systems can be interpret as incremental constrain over the modal space generated by causal development. References Mumford, S. & Anjum, R. L., (2011). Getting Causes from Powers. OUP Oxford. Mumford, S., (1998). Dispositions. Oxford University Press. --- (2009). Passing Powers Around. The Monist 92 (1):94-111. Mitchell, S., (2003). Biological Complexity and Integrative Pluralism. Cambridge Univ Pr. Nagel, E., (1979). Teleology Revisited and Other Essays in the Philosophy and History of Science. Columbia University Press. Sloman, A., (1996) Actual possibilities. In Principles of Knowledge Representation and Reasoning: Proceedings of the Fifth International Conference (KR'96). Morgan Kaufmann Publishers. http://www.cs.bham.ac.uk/research/cogaff/96-99.html#15 Wright, L., (1973). Functions. Philosophical Review 82 (2):139-168. ---(1976). Teleological Explanations: An Etiological Analysis of Goals and Functions. University of California Press. followed by 5 minute break. E: Approx 3:50 Comments from Al (and presentation of some of your own ideas if you wish) How long would you like? F: Comments by Alex on discussion so far G: General discussion END: approx 5pm, though if we over-run I expect the room will remain available.
School of Computer Science
The University of Birmingham