 At the time, I did not realize this trade-off between liberty and security was actually a centuries-old motif, one brought to us initially, or at least most influentially, by the philosopher Thomas Hobbes. In his book Leviathan, published in 1651, he made an argument that has been pivotal in shaping our modern conceptions of security and shifting the dominant understanding away from that stoic concern with mental calm toward the need for physical security in a strong centralized state.