I’ve always been fascinated by the way cats go about their lives, as if they’ve got it all figured out from the start. There’s something about the way they strut around, seemingly unbothered by what others think, that makes me wonder if they’re the real philosophers among us. According to John Gray, who wrote a book called “Feline Philosophy, Cats and the Meaning of Life,” cats don’t need systems of morality or complicated ideologies to live well. They’ve got their own natural code. We humans...