For centuries, long before modern courts and forensic science, justice was decided in a far more terrifying way.

The accused were forced to drink poison.

If they survived, they were declared innocent.

If they died, their guilt was sealed forever.

Across the ancient world, powerful plants became instruments of truth ? serving as judge, jury, and executioner across civilizations that never knew each other existed.

From the cup of hemlock that ended the life of Socrates in ancient Athens, to the Calabar bean trials of West Africa, to the terrifying tangena ordeals that killed tens of thousands in Madagascar, to the Datura interrogations of colonial India and the aconite trials of imperial China ? entire societies placed their faith in the lethal verdicts of nature.

In Judgment by Poison, Gary Logan uncovers the true history of the deadly botanicals that shaped systems of justice across the ancient world. Blending historical investigation with the toxicology behind each plant, this book reveals not only what these ordeals were ? but why some people lived and why some people died.

The answer had nothing to do with guilt.

Survival depended on chemistry. On dose. On fear.

The plants never lied.

But justice rarely survived the trial.