This is not as solid as it sounds however, because we can still interpret (even) interacting elements as virtual elements.
When the elements are separately and freely, i.e. individually, existing, then they are of course actually existing. But when they are included within a whole, i.e. integrated in such a whole, then they can be interpreted as existing only virtually in that whole, but -- dependending on the degree of unity of that whole -- they will exist so in several possible degrees (of virtuality). To exist virtually, means existing in a near potency with respect to the way of existing in the case of freely existing elements or parts. This "near" can come in several grades. In many cases we will have wholes that show only a moderate degree of integration of its parts (elements), implying a very near potency of those parts with respect to what they should be if freely existing. The actuality, seemingly present in those parts of such a weaker whole, is nevertheless always the actuality of the whole. Stronger degrees of integration correspond with more remote potencies of the elements with respect to their way of existing when separated from each other (i.e. when the whole is disintegrated). It takes more effort to set those parts free and convert them qualitatively into the originally freely existing elements. Such a stronger degree of integration of the parts within the whole corresponds with a stronger degree of unity, of totality, of Substance.
In every whole, be it weakly or strongly expressed as such, the parts are in fact not parts, i.e. not things, anymore but properties of that whole. In perfect wholes (if they exist at all) the potency of the parts is maximally remote. In the case of conserved properties, some properties of the parts (elements) have become properties of the mixtum, other properties have disappeared (the latter is clearly demonstrated in the case of the generation of a chemical compound). So instead of parts we now have a distribution of qualities across the whole. These qualities are actual. In the case of moving parts, one distribution of qualities is replaced by another. The action involved here is always the action of the whole.
The possibility of grading with respect to the unity of a whole is not discussed by HOENEN. In his view something is either just an aggregate or a true Totality.
.