evidence: "Virtues are formed in man by his doing the actions," Aristotle said. The writer Will Durant interpreted it thusly: "We are what we repeatedly do… therefore excellence is not an act, but a habit." In other words: Excellence isn’t this thing you do one time. It’s a way of living. It’s foundational. It’s like an operating system and the code this system operates on is habit. [...] We’re inviting you to spend six weeks challenging yourself to change what you "repeatedly do." And we are promising that if you can do that, you can achieve arete—personally and professionally.