The opposite of good is evil. But, as Hannah Arendt and others point out, generally, it is not malevolence that leads to evil; instead, it grows from passivity and conformity.
Evil is born of taking the easy path too often, assuming too much, and avoiding painful efforts.
That is to say, evil is evolutionarily natural: the less you struggle, the more calories you conserve. However, society is not based upon entropy and conservation but effort and consideration staving off casual collapse.