"Are we allowed to (insert dumb idea here)?"
Do you answer with a policy, or with a principle?
Policy has the advantage, at least initially, of being simpler than principle. For a new employee, to just say "no, you can't do that" takes much less effort than teaching why that might not be a good idea, and when it might be okay. For an organization, policy has the advantage of being enforceable -- a company can protect itself against outside action and internal exploitation with policy.
But over time, policies pile up. A small set of good ideas becomes an unwieldy and often contradictory mess of rules that may make no sense because they lose their context. And a snap policy decision can gloss over subtle distinctions that might justify deviations. When experienced employees who understand the reasoning behind the policies make needed deviations, younger employees inadvertently learn that it's okay to break the rules.
Principles, on the other hand, 'empower' employees in the true sense of the word. And in the long run, that improves organizations. Employees who understand the reasoning behind answers to their questions become able to apply that knowledge to other situations without having to ask for further, specific guidance. Principles do not multiply -- they strengthen and deepen.
"But," the company argues, "our employees won't follow principles properly! We need clearer policy that we can rigidly enforce without being accused of discrimination or selective enforcement or unfairness!"
If your people won't learn and follow principles, you do have a choice -- either become an organization that relies on policy to control all employees, or become an organization that removes poorly performing employees and allows motivated and intelligent employees freedom to act. Before you make that decision, though, it would be wise to look at your own approach to teaching the principles that employees ought to be following. Are you actually teaching those principles well?
Teaching principle is harder than teaching policy. Policy can be taught in Powerpoint. Principle can only be taught in practice, experience, and over time.
But principle is the better path.