mutual opposition(n = noun.linkdef) polarity - a relation between two opposite attributes or tendencies; "he viewed it as a balanced polarity between good and evil"
is a kind of oppositeness, opposition

antipodal opposition, coefficient of mutual induction, diametrical opposition, gradable opposition, in opposition, in opposition to, mutual, mutual affection, mutual aid, mutual attraction, mutual company, mutual exclusiveness, mutual fund, mutual inductance, mutual induction, mutual resemblance, mutual savings bank, mutual understanding, opposition, opposition party, orthogonal opposition, polar opposition, ungradable opposition