That quote is mine, though the idea has been around for centuries.
It is my own personal philosophy for making many important decisions. The best example is probably the choice of political ideology. Let us say we have a Left-Right grid.
Pure communism would collapse in about a decade.
Moderate communism would fail in a couple of decades.
Socialism would decay in a couple of centuries.
Moderate Capitalism would decay in a couple of centuries.
Pure Capitalism would fail in a couple of decades.
Anarchy would fail in about a decade.
Obviously the ideal way to govern a nation lies in the balance between it all. The core values of capitalism must be kept, but it needs to be balanced with socialist policies...EQUAL Public Education, Public Highway System, Protection against Monopolies, Protection against Corporations taking away millions of American Jobs and giving them to foreign slaves, I mean workers (This is what will destroy us in about 50 years if we don't stop it.), Laws, policies, and programs enacted to allow TRULY EQUAL opportunities for all, etc...
You can also apply it to science vs religion.
Or light vs dark, good and evil.
Those are the three biggies that I choose to use the balance philosophy in my life.
I hope that answers your question.
"All answers lie in the balance."