General James Mattis on leading in a crisis and thriving in the next normal | McKinsey & Company

"Good feedback loops and data displays are critical. You have to start with data. If you can only quantify 10 percent of the problem right now, then start there. As more data comes in, you replace assumptions with knowledge. Then you need to apply your judgment.One of the most important things is keeping someone at your side who will challenge you to balance the quantitative and non quantitative inputs to your assessments, who will watch for gaps in your assessments."