The Taijitu, or yin yang symbol, is the symbol of Taoism. It represents balance and harmony. The symbol is composed of two halves representing opposites in union with a bit of their counterpart in the center of each half.
This should not be taken as a symbol of conflict or cycles, because the two halves are in fact the whole and cannot be separated without becoming nothing. Much like a tapestry, you can see the individual colors, but if you were to unweave them, you would have nothing but some twisted string.
Two concepts that the Taijitu never represent are good and evil. Though this belief is popular in the west it should be noted that the concept, as we understand it, of good and evil is not originally a part of eastern philosophy. For example, the day can burn as well as grow crops, and the night can comfort as well as frighten. Neither day or night is truly good or evil, they simply are, and yet it is when the two fall out of balance that conflict arises. Thus righteousness and wickedness cannot be defined simply by the way a subject in question acts upon us. This is especially true when the subject is simply obeying its given nature with out malice or mercy.