It could be said that the degeneration theory and theories similar to this theory are the most extreme examples of social death. The idea of degeneration has been popular in both right-wing and left-wing politics. Both left-wing and right-wing politics have used the word decadence to describe social groups whose social, moral, religious, aesthetic, or political commitments tend towards the inhibition of any or all forms of progress (as used by some critics on the left to describe their opponents on the right) or towards the undermining of fundamental forms of order (as used by some critics on the right to describe their opponents on the left). In either political optic, the forces of decadence may be internal or external; internally, the members of political opposition may represent those who have allowed essential ideals to lapse from their view of the world; externally, members of another society may be considered as cherishing ideals which introduce forces of collapse into the worlds wherein they are immigrants.