Composition-as-identity, causalism and Peter van Inwagen’s Special Composition Question

If composites (i.e., objects that contain proper parts) are identical to the sum of their compositions (i.e., collections of objects that compose the composite), then causalism (i.e., the principle that each object is a cause or caused) provides us with a swift answer to Peter van Inwagen’s Special Composition Question (i.e., under what circumstances does a collection of objects compose a further object?). The answer would be that a sum of objects is an object if and only if the sum as a whole causes another object or was caused as a whole by another object. (Towards a Renewed Case for Theism, 2012, pp. 125-6)