The pencil - wonderful.
Borrowed from Milton Freidman, a hero for freedom. He was a genius, and a hero. His genius was to simplify what the other side tries to obfuscate and complicate.
https://www.google.com/search?q=milton+friedman+pencil&rlz=1C1UEAD_enUS1188US1188&oq=milton+friedman&gs_lcrp=EgZjaHJvbWUqBwgFEAAYgAQyBwgAEAAYjwIyCggBEC4YsQMYgAQyBggCECMYJzIGCAMQIxgnMgoIBBAAGLEDGIAEMgcIBRAAGIAEMgcIBhAAGIAEMgcIBxAuGIAEMgcICBAAGIAEMgcICRAuGIAE0gEJMjM2MjFqMGo3qAIAsAIA&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:d6636683,vid:67tHtpac5ws,st:0
Yup, I was an Econ major and studied Francis Hayek too.