To help leaders to be rigorous even without figures, great philosophers have lots of ideas. Managers are invited to rediscover the art of thinking. They should understand the role of mental models, realize the importance of cognitive bias, agree on clear definitions and efficient criteria etc.
Creativity demands the ability to unshackle ourselves from conventional ways of thinking, to "think outside the box". But we need to go a step further. Once outside the box, we need to construct a new box or boxes (that is, new intellectual frameworks or models) to help us structure our thinking. Only once we have done so can we generate truly game-changing ideas.