I was reading an analysis of Federalist 67-77, ascribed to Alexander Hamilton, in which he asserts and defends the need for a national executive (the President), as opposed to simply relying on a legislature for national leadership. I did not know that under the Articles of Confederation that preceded the Constitution there apparently was no executive.
Hamilton highlighted an interesting fundamental difference between the two in function: a legislature is given to deliberation which is appropriate and an executive is given to action which is also appropriate.
Any group or organization needs both. Leaders who charge forth without any sense of discussion, consensus-building, or deliberation eventually wear out the mature. Group members who only deliberate and never make a decision to act wear themselves out as well.
I have found a third trait at work: when a group gets too large, opinions actually stop rather than proliferate. Bible talks I have led (or staff groups, etc.) with 4-6 people produce remarkable innovative thinking; but when the room is full of people–10-15–it’s difficult to speak up more than once in an hour or so!