"Nobody ever did anything very foolish except from some strong principle". I chanced upon this quote a couple of months ago, and it has stayed in my mind ever since. It is an old quote, by the 2nd Viscount Melbourne, the young Queen Victoria's political mentor, but it has stayed in mind because it feels contemporary, and is less cynical than it sounds.
Good principles - like, for instance, that all human beings are created equal - tend to be very abstract. It is never obvious how these abstract principles translate into programs of specific action, into doing. However, it is always tempting to invoke these principles to build support for a program of action.
The problem with linking an action plan closely with its animating principle is that it makes it harder to abandon the action plan, which is a pity, because only certainty with any action plan is that it will be made to look silly by "black swans", by real-world conditions that the plan did not, and could not have, known about. The bigger the agenda, the more quickly the black swans will strike.
A program of action which is tightly linked to a cherished principle usually means a program of action that isn't adaptive enough. von Moltke the elder was pointing in the same direction when he said "No battle plan survives contact with the enemy"