Umut Akova
Ankara, Turkey

Socrates (469–399 BC) was the ancient Greek philosopher most often credited with pioneering Western philosophy and with founding the Socratic method, a dialectical approach to questioning and critical thinking. Known for his pursuit of ethical truths and moral principles, he engaged individuals in open-ended discussions that often revealed contradictions in their beliefs. He believed in self-examination and the importance of questioning assumptions, which led to his famous declaration, “The unexamined life is not worth living.” He left behind no writing of his own. Instead, his philosophy was widely documented by his followers, most famously by Plato, Xenophon, and Aristophanes. Socrates did not conform to conventional Athenian norms. He dressed modestly, prioritized intellectual pursuits over material wealth, and was uninterested in traditional Athenian religious practices. This led to accusations of corrupting the youth and promoting impiety, which ultimately led to his trial and execution via hemlock in 399 BC.¹

The trial and death of Socrates has been subject to many artistic renditions, perhaps most famously by Jacques-Louis David in oil painting his The Death of Socrates. This neoclassical painting from 1787 depicts Socrates at his execution. He is surrounded by pupils and friends in distress. Having had the opportunity to flee Athens, he instead uses his final moments to teach one final lesson to his pupils while being handed a glass of what is assumed to be poison hemlock. The type of hemlock that is assumed to have been used is Conium maculatum, commonly known as “poison hemlock” or simply as common hemlock.² Hemlock contains at least twelve closely related neurotoxic alkaloids, chief among them coniine.³ Coniine, when ingested, preferentially binds to nicotinic acetylcholine receptors where it acts as an antagonist, thereby blocking the response of muscles to acetylcholine. It stays bound to such receptors on the neuromuscular junction and prevents their polarization, resulting in nicotinic toxicity and muscular paralysis. This paralysis usually starts from the lower limbs and ascends though the body. Death occurs due to hypoxia from respiratory paralysis.⁴ These symptoms are consistent with those described by Plato in Phaedo. Although lethal in relatively small doses when ingested (only 3 mg is enough to produce symptoms of toxicity), hemlock has also been used topically, especially in antiquity, as a therapeutic for a variety of conditions⁵ such as herpes, erysipelas, rabies, and cancerous ulcers. It was even included in the British Pharmaceutical Codex until 1934, and its removal is speculated to be because of variation of potency and availability of less toxic substitutes.⁶

References

1. Kraut, R. Socrates. Encyclopedia Britannica; 1999.
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3. Daugherty CG. The Death of Socrates and the Toxicology of Hemlock. Journal of Medical Biography 1995;3(3):178-82. doi:10.1177/096777209500300310.
4. Dayan AD. What killed Socrates? Toxicological considerations and questions. Postgrad Med J. 2009;85(999):34-7. doi:10.1136/pgmj.2008.074922.
5. Hotti H, Rischer H. The killer of Socrates: Coniine and Related Alkaloids in the Plant Kingdom. Molecules 2017;22(11):1962. doi:10.3390/molecules22111962.
6. Bowman WC, Sanghvi IS. Pharmacological actions of Hemlock (conium maculatum) alkaloids. Journal of Pharmacy and Pharmacology 1963;15(1):1-25. doi:10.1111/j.2042-7158.1963.tb12738.x.