Although value clusters generally work together so that various values reinforce one another, at times, these clusters of values may also include values that contradict one another. Value contradictions can arise between individual and communal value systems. That is, as a member of a society, group, or community, an individual can hold both a personal value system and a communal value system at the same time. In this case, the two value systems (one personal and one communal) are externally consistent provided they bear no contradictions or situational exceptions between them.
Value contradictions can also arise within individual or communal value systems. A value system is internally consistent (value consistency) when its values do not contradict each other and its exceptions are abstract enough to be used in all situations and consistently applied. Conversely, a value system by itself is internally inconsistent if its values contradict each other and its exceptions are highly situational and inconsistently applied. A value contradiction could be based on a difference in how people rank the value of things, or on fundamental value conflict. For example, although sharing a set of common values, such as hockey is better than baseball or ice cream is better than fruit, two different parties might not rank those values equally. Also, two parties might disagree as to whether certain actions are right or wrong, both in theory and in practice, and find themselves in an ideological or physical conflict.
Conflicts are often a result of differing value systems. An example conflict would be a value system based on individualism pitted against a value system based on collectivism. A rational value system organized to resolve the conflict between two such value systems might take this form: Individuals may act freely unless their actions harm others or interfere with others' freedom or with functions of society that individuals need, provided those functions do not themselves interfere with these proscribed individual rights and were agreed to by a majority of the individuals.
Protestors clash with police at the 1999 WTO summit in Seattle
People whose personal values conflict with communal values may try to change communal values through protest.
Life of George Washington--The farmer
This picture, by French artist Régnier, shows George Washington standing among African American field workers. The practice of slavery represents a value contradiction between wealth and liberty.