An open palm is a kind of paradox, isn’t it? It’s so inviting, so yielding: “Hands up,” after all, is the international motion for surrender. But there’s also a parallel universe of symbolism—a sense of mystery—hidden within that soft flesh. There can be an appeal to divinity in the open palm, a belief in a higher power. Look at all those saints in Christian art, their palms raised to the sky as they exhort God. The open palm can also be an act of violence, of interpersonal warfare—a slap across the cheek.¹ Or it can be an act of community—the handshake, two palms meeting each other in a gesture of goodwill.

As far as forms of divination go, palmistry might not be having quite the same renaissance as astrology or tarot, but it’s probably even more accessible—we ha...