1. The following argument applies only to cases where the elements are conceived as making up a complete set. It does not apply when the elements have been selected (possibly as a sample) from a larger set. Where the elements are selected on a priority basis, as being the "most important", the argument only applies when this may be interpreted as implying most "fundamental" or "basic" [1].

Ideally the argument should also apply to any numbered list of points in an argument. But, since numbers are usually allocated for convenience to provide a simple structure to a sequence of paragraphs (and only indirectly related to the concepts developed), this is seldom the case. It should however apply wherever the author(s) declare that: "The following points apply", provided "including the following points" is not used or implied. The list of points should therefore have been elaborated through a "struggle" to get the best "fit"--a struggle which may have required much more than superficial reflection over a short period of time [2].

2. The sets under consideration contain elements which are essential to the ordering of an equilibrium state or an evolving process (especially in the psychosocial domain). As such each element is different and has a special part to play. Each complements the others and all are conceived as essential (e.g. in the case of human values or needs). There is a desire that such sets should be well-formed or well-ordered, even if some degree of "fuzziness" must be tolerated as the content is clarified through research and debate.

3. The elements in such sets should be equally distinct from one another or else the question arises whether two or more similar elements should not be redefined as one. This said, however, two cases must be distinguished:

• the set itself may well be made up of sub-sets whose elements have characteristics in common
• some elements may be more directly related to others whilst still being distinct from them.

Any ambiguity implied here should be resolved by the form in which the set is represented (see below; also in Part 2).