2000 BC: Here, eat this root.
1000 AD: That root is heathen! Here, say this prayer.
1865 AD: That prayer is superstition! Here, drink this potion.
1935 AD: That potion is snake oil! Here, swallow this pill.
1975 AD: That pill is ineffective! Here, take this antibiotic.
2000 AD: That antibiotic is poison! Here, eat this root.
Always remember, the medical profession refers to their business as a "Practice"....