Another far-left cause, another riot and clashes with police.

Police used "flash bangs" and pepper spray against some protesters who pelted them with rocks and bottles late Wednesday, as violence erupted during May Day in Seattle.

Several dozen protesters, many using bandanas to cover their faces, began clashing with police in downtown Seattle hours after a peaceful immigrant-rights march ended.

The May Day protests in Seattle the previous year turned violent as well and in Los Angeles several years before. It's not just May Day either--let's not forget to mention the infamous Occupy Protests. There's something about anti-capitalism that brings out the worst in people.

When the "far right" protests? Millions of people in lawn chairs waving flags at Tea Party rallies.

That not only is strong evidence for the civility of their guiding ideology, but is an indictment on the media.

Can you imagine if a Tea Party rally turned as violent as a May Day or Occupy protest, with pepper spray and fires and vandalism? It would be front-page news for weeks.

But when the far left does it, it's just protesters being protesters. More of the usual--which is a sad commentary on that political ideology.

I wish Earth Day and May Day were on the same day, because then it might be easier to persuade liberals of the errors of their ways.

It's sometimes hard to get through to people with a different ideology than yours, so sometimes it helps to speak to them in their own terms. Since Earth Day environmentalism and May Day anti-capitalism go hand in hand and the two days are close together on the calendar, let's discuss capitalism in terms of environmentalism.

Environmentalists don't want delicate ecosystems impacted by mankind's intrusion into nature. One small environmental change brought on by humans may impact the mating habits of some rodent, which causes fewer rodents, which impacts the eating habits of an animal one link higher on the food chain, and so forth until the ecosystem is destroyed.

Almost all organisms enter into relationships with one another where their growth and survival often depends on other their symbiotic relationship with other organisms. Flowers are colorful to attract bees, and bees spread the pollen to other flowers. The bees flourish and so do the flowers.

 Humans also enter into symbiosis with other humans. Two people, two groups, two classes, or two nations may work together to advance mutual interests, even the "99%" and the "1%". Poor and middle-class people are typically paid by rich people to perform some function at some company, a company that usually makes ever-more affordable items that the poor and rich people can buy to further enhance their quality of life.

Both groups benefit, like bees and flowers. However, those in the Occupy Movement and other socialists see this relationship as exploitative. They view the relationship between the wealthy and the non-wealthy in terms of parasite and host. One takes from the other without providing any benefit.

Ironically, there's ardent support on the Left for those that take much from others but don't contribute much themselves-- the chronically unemployed, chronically dependent, criminals, and regulators.

Instead, the view the parasites as those that started companies that employ many people and create products that people want at prices they are willing to pay for them.

Their solution is to upset that ecosystem with a heavy hand, something they would never do to other natural relationships, completely oblivious that when you impact one link of the food chain you impact them all, often to the detriment of every organism in it.

In introductory biology classes we learn that ecosystems are made up of producers and consumers. It's no coincidence the same terms are used in economies as well. Progressives would do well to take their conservationist approach to the environment and apply it to the economy.