Let’s acknowledge it: Life is tough. Most people struggle to make a secure living, stay healthy, and care for family members. On a larger scale, climate change keeps unfolding, Ukraine is under attack, authoritarianism is gaining ground around the world, and a pandemic has disrupted society. How are we supposed to feel good amid all this? Well, you might not feel good. But you can still live a good life. That is a central message of “Life Is Hard,” a new book by MIT Professor Kieran Setiya, recently published by…