My father’s definition of the range of ideology is this:
I believe personality definitions are spherical in nature and can be defined by spherical equations (and a sinusoid). The far fringes meet and touch on the other side of reality. Once you get past + (conservative) & – (liberal) 90 degrees (reality) you slowly progress into non-reality until at 180 degrees the right and left non-realities meet and in essence are the same in actions and deeds.
As far as I can recall we’ve never discussed this subject but I’ve held the same belief for several years. It’s easy to see that as radical groups get farther and farther from the center they begin to embrace the tactics and values of their arch-enemies.
Nowhere is this more easily seen and understood than with ultra-liberal progressives whose highest values ought to be logic, freedom for the individual, and above all free speech and inquiry.
Yet on what American conservatives casually call the far left progressives have embraced the thinking of both the fascists and the communists in their strident, unrelenting efforts to confine individuals personal, speech, and inquiry rights to their own narrow range of beliefs.
Conversely this phenomenon can also be seen in ultra-conservative religious groups in which individual is expected to have both an intimate personal relationship with God and give his/her all to the group in order to create a perfectly selfless society. All too often these groups end up taking on the characteristics of godless anarchists, as in the case of Jim Jones and today’s radical Muslims.
The ring theory of ideology isn’t a perfect analogy; groups all over the continuum plagiarize and bastardize both their own and others’ belief systems as they age more or less well. But it is more useful to think of politicized groups as aligning around a circle rather than on a linear spectrum. While the far ends of left and right disagree on the specifics of their grievances, the means they use to advance their agendas are remarkably similar.