A manager argued that he could either increase his business unit's margins or its sales, but not both. His chief executive reminded him of the time when people lived in mud huts and faced the stark choice between light and heat: punch a hole in the side of your hut and you let the daylight in but also the cold, or block up all the openings and you stay warm but sit in darkness. The invention of glass made it possible to overcome the dilemma to let in the light but not the cold. How then, he asked his manager, will you resolve your dilemma between no sales or no margin improvement? Where is the glass? From the Introduction "To win, leaders have to push their companies beyond trade-offs. They must find strong growth at premium returns, not one or the other. They must deliver great results today and build for the future at the same time, not push for earnings that can't be sustained. The Three Tensions is about having both at the same time, more of the time. I recommend it to any manager serious about winning." James Kilts, former chairman, CEO, and president, The Gillette Company "Leadership can't be just about telling people what you expect of them. The Three Tensions sets out a range of helpful tactics leaders can adopt to really engage their people in the search for good performance on many fronts." Andrew Cosslett, chief executive, InterContinental Hotels Group PLC "The Three Tensions speaks to fundamental management issues, perhaps the most fundamental. Managers looking for new ideas on how to improve performance will find it very stimulating. I found my own thinking very much influenced by it." John Roberts, professor of economics, strategic management, and international business, Stanford Business School