When we want to change the world we’re usually reacting to a problem. Even positive visions usually come out of negatives. We want liberty because we have tyranny. We want health because we have sickness. We want prosperity because we have poverty. We want equality because some people have way more than they need and others less than need.
When we solve a problem it’s generally mediated by a principle. Very often the principle is just the problem stated slightly differently.
Problem: Some people have more than they need, others have less than they need.
Principle: Make sure no one has more than they need while anybody has less than they need.
A principle tells you, generally speaking, what you should be doing about a problem. It doesn’t tell you how to do it.
So, for the example above, post-war Welfare states generally came upon the solution: