The difference between genius and stupidity is that genius has its limits.
2000 B.C. – Here, eat this root.
1000 A.D. – That root is heathen. Here, say this prayer.
1850 A.D. – That prayer is superstition. Here, drink this potion.
1940 A.D. – That potion is snake oil. Here, swallow this pill.
1985 A.D. – That pill is ineffective. Here, take this antibiotic.
2000 A.D. – That antibiotic doesn’t work anymore.Here, eat this