Principles are ways of successfully dealing with reality to get what you want out of life.
Ray Dalio, one of the world’s most successful investors and entrepreneurs, cites principles as his key to success.
No matter how good you are at hiring, some of your hires won't work out. Know how the people you're considering operate and visualize how that will produce successful results. Knowing what they did is valuable only insofar as it helps you figure out what they are like.