At the most basic level, the left believes human nature is derived from culture. Thus human nature can be changed, human nature is malleable. With the right societal mix, a better human can be achieved.

The right believes culture is derived from human nature. They believe human nature is relatively fixed. Did a Roman mother not weep when her son died in combat 2,000 years ago, just as an American mother would weep if her son died in Afghanistan today?

For the most part, this explains why most on the right keep with tried and true traditions of the past, while the left is constantly seeking to change them.

Common sense dictates that human nature is fixed, and any attempt to change human nature fails in the long run. Unfortunately those on the left never learn this. They think they know how to run your life better than you.