"Doctor, I have an ear ache."
2000 B.C. - "Here, eat this root." 1000 B.C. - "That root is heathen, say this prayer." 1850 A.D. - "That prayer is superstition, drink this potion." 1940 A.D. - "That potion is snake oil, swallow this pill." 1985 A.D. - "That pill is ineffective, take this antibiotic." 2000 A.D. - "That antibiotic is artificial. Here, eat this root!"