Values and self-identification are crucial for understanding human action, both in actuality and potential. Value systems, whether reached by reflection or constructed by others and attached whole to one's weltanschauung by being seen as valuable in themselves, inform how people act and their notions of their personal and society's good. Value conflicts are commonplace; value systems attempt to simplify (and in some cases make public) the deliberation over conflicting values done near the time of decision. Values may have many origins, foci, and other types of status in the mind, and depending on one's inclinations, one may choose not to identify with some of one's values - addictions and temptations are often posed as being external to the self when one speaks of struggling with them, while in other cases people avoid situations that would likly lead them to comprimise their value system because they fear temporary shifts in the weight of some values caused by immediacies.
A person alone on an island has less of a need for a complex value system - for them, a number of types of values don't need to take their full form. In a society, a full theory of mind suggests values that relate to societal ideals must join consideration in systemisation of values. One of the functions of culture and law is to shape and limit the use and types of struggle people have with each other, another is to act as a fabric for norms (both cultural and legal). As people are typically raised in a culture, they have a tendency to cluster around the the norms of their upbringing. One of the continual tasks of society is to keep the value systems people develop within broad limits of each other (or to bring them into that state) - various mechanisms fill this roll, from civics classes and parental upbringing to organisations (some religious). True uniformity in this regard is not necessary and very rare in practice, and usually the (theoretical) centre of values around which variance revolves is much larger in scope than what is encoded into law or hard custom. Custom and law serve as buffers against acts based on value differences between individuals, providing structure for discussion over contention and potential remedies for injury that violates societal norms. From an individual perspective, organising one's value system so as to make clear what rememdies one pursues (or sanctions) in situations of conflict acts as a philosophical good.
Apart from the actual values one holds in one's system, for those who take the effort to debate on value systems or revise their own, typically one holds values and value conclusions that govern that process. We define these as metavalues - while they are as variable as actual values one holds, they play a different role in one's thinking, forming criteria for evaluation of value systems in general and help determine how comprehensible and respectworthy other value systems are to us. Metavalue conclusions may range from the thematic (e.g. emphasising the individual), the logical (e.g. being simply and "justifiably" derived from explicit values), to the structural (e.g. the types of frameworks the values are fit into). Disagreement on values and metavalues are potentially orthoganal to each other, although in many cases we might find substantially similar value expressions entering one's thought in both systems.
Complex values are partial value-conclusions that take the shape of values in a value system - like other value-conclusions, they are derived through (or at least derivable from) the interaction of values in the framework suggested by one's metavalue theory. We define base values as values not derived from other values, and note that they are philosophically atomic - the origin of base values and their weights in an individual is not a question of value philosophy, nor can principled arguments be made against any individual values as such principle is itself dependent on values (whether meta or actual). Arguments that would sway people on those matters are aesthetic if honest, sophistry or propoganda if not. This "lack of solid ground" does not make unnecessary the struggle over values or mark them as unimportant.
The opportunity to reconsider one's value system and rework parts of it is not different in principle from the "twilight of the idols" or the "renumeration of all values" Nietzsche suggests - the differences are primarily in style and scale. Education in a functioning society involves passing a default pedagogy on values to children, which they acquire in stages and interpret in later stages. Insomuch as they accept an external value authority, they attach with metavalues a body of value conclusions into their worldview, mixing it and interpreting it in light of whatever value conclusions they come to on their own. Similarly, values can have deeply biological origins - some desires such as sex, companionship, and physical security are common to most of humanity, and the effects of sacrificing these values when they conflict with others can be more dire than other value conflicts.