2019-03-01, 05:37 PM
Real Dispositions in the Physical World
Ian J. Thompson
Ian J. Thompson
Quote:The role of dispositions in the physical world is considered. It is shown that not only can classical physics be reasonably construed as the discovery of real dispositions, but also quantum physics. This approach moreover allows a realistic understanding of quantum processes.
Quote:A distinction (note 1) is thus made between the 'Principal Cause' (that disposition which operates), and the 'Instrumental Cause' (that circumstance by means of which dispositions operate). Principal causes operate according to instrumental causes. Both are necessary for any action, for example, when a stone is let fall: the principal cause is the earth's gravitational attraction, and the instrumental cause is our action of letting go. Its hitting the ground is thus caused by our letting go, but only as an instrumental cause. Many common uses of 'cause' refer to instrumental causes rather than principal causes, as it is only in the instrumental sense that events can be said to be causes.
The next point to note is that dispositional properties can only be explained or reduced to other dispositions, not to entirely static or structural properties. That is, dispositions have a 'categorical irreducibility', as it is impossible to explain them away in terms of other categories such as space, time, form, process, material, property etc. For suppose that the exact shape and size of an object were known, the shapes and sizes of all its constituents, along with a list of these facts at every time. We would still know nothing about how or why the object would change with time or on interactions. Still less could we predict how it would respond to a new experimental test. In fact, if it and its parts had no dispositional properties, as Hume would argue, then we have his conclusion that any actions or changes (apart perhaps from uniform motion) would be entirely inexplicable: there would be nothing about the object that could lead to these changes rather than to any others.