Evolution of medicine
“I have a headache...”

2000 BC – Eat this root.
1000 AD – That root is infected. Say this prayer.
1850 AD – That prayer is superstition. Drink this potion.
1940 AD – That potion is snake oil. Swallow this pill.
1985 AD – That pill is ineffective. Take this antibiotic.
2000 AD – That antibiotic is artificial. Eat this root.

Internet: <www.geocities.com> (adapted).