As the ultimate constituents of our universe of discourse are attributes, we are formally faced with a problem of concretion. (See 1.2.2) But, actually, we have started the other way around, namely with the assumption that complex, concrete things have both component parts and attributes, and those parts in turn also parts and attributes. We have thus considered complex things and their parts to be of the same ontological category, since they all have parts and attributes as their elements. Yet, whereas complex things have attributes, attributes never have things of that same category: a table may have a weight, but (a) weight cannot have a table. (It may belong to one at the most.) In subdividing complex things into smaller things (parts of a lower type) we have first formed a picture of abstraction which looks like the one in figure I.1.4.2.1.

The crucial theoretical question is now whether we do arrive in this way at components which are mere sets of attributes (but which have relations as well). Without such an end to the abstraction process one might object against the 'categorical' discrepancy between things as parts and attributes and maintain that this discrepancy remains, however far down the components are subdivided into their elements. But then, one should bear in mind that the question whether the difference is categorical from any ontological point of view is the very matter at issue here. If parts and attributes can never be taken as ultimate elements of one and the same thing, the aversion of this sort of combination may be the very reason to postulate that there is an end to the abstraction ladder so that all parts, that is, all things, only have attributes as their ultimate factors, tho certainly not as their elements or components.

A second point to take into consideration is that in the beginning the things of our domain were phenomenal or material things such as pens and fingers, but if there is an end to materiality when subdividing these things, there should be borderline cases. And indeed, there are such borderline cases: elementary particles do not have 'material', that is, constituent parts, and fail to count as bodies in this respect. They are not material in that they are not decomposable into matter, and yet they are material in that they are components of matter. It is here where we have arrived at a level where we can merely speak of an object's purely physical attributes and relations. And it is here where mass and energy become one and the same, where the material world transubstantiates to become immaterial. At this level objects are purely 'intensional', precisely like attributes, in that they have no extensional elements anymore. If this is not correct for particles such as neutrinos, one may assume that it still applies to 'truly' elementary particles, unless one is absolutely unwilling to ever accept the existence of such simplex objects.

By choosing attributes as the ultimate constituents of the first and all other domains of discourse we have implicitly postulated that there is an end to the abstraction ladder. That there is, then, a beginning of a concretion ladder amounts to the same: to approach the problem of concretion we are faced with we reverse the picture of abstraction. In general, every realist constructional system needs at least one primitive relation which will make it possible to differentiate systematically between those abstract qualities (such as attributes) which form concrete things and those which do not. As the basic concreting relation one might choose togetherness, in our case among attributes, which obtains between any two attributes belonging to some one concretum or thing in general. (Choosing having as primitive does not make a difference: two qualities are 'together', if they are 'had' or possessed by the same thing.) If the relation of togetherness did not hold between any two attributes of a set (that is, if they did not belong to one and the same thing), the set in question would simply not be ontic, that is, (trivially) would not exist as a thing. The notion of togetherness can subsequently be extended to obtain not only between distinct, atomic qualities, qualia or elements but between every two discrete elements of a concretum or other thing. The elements may be component parts or attributes of the whole. In our constructional system a concretum may be conceived of as a single physical body with all its parts and its (whole-)attributes. All the elements of such things 'are together', that is, bear the relation of togetherness to each other, but the whole itself is not a part of another thing in which it bears the same relation of togetherness to other things. In a biological or physical sense human beings, for instance, are concretums but humankind is not a concretum.

An old metaphysical issue is that of the distinction and relation between instance and quality. But as the 'atoms' of our constructional system are attributes we have no problem since they are 'fully repeatable, universal individuals'. The instance/quality distinction is in our case an instance/element distinction. Whether we regard a whole as an instance or as an element (component) simply depends upon whether we are concerned with its relationship to its attributes (those belonging to its predicament) or to a whole of which it is itself a component part. In our system instances of a property or attribute are never entirely separate. They may be discrete in space-time and in every other respect, yet they still have at least one common element: the common attribute itself. As has already been rightly argued before, attributes are not metaphysical sums of various particles which would occur in several instances. When concrete individuals which are believed to stand wholly by themselves 'participate in' a single property, their similarity is due to identity between at least one of their predicative elements. This could be shown diagrammatically by having the predicaments of the things in question overlap, by drawing the identity relation between one or more predicative elements of these things or by giving identical and unique names to identical and unique elements.