Achilles Heel

The Definition

A single, critical point of vulnerability in an otherwise strong or powerful person or system. It describes the "one thing" that can bring down a giant.

The Deep Dive

This phrase is a direct "heir" to one of the most famous stories in Greek mythology. Achilles was the greatest warrior of the Trojan War, a man of such immense strength and skill that he was considered nearly invincible.

According to the most popular version of the myth (which was actually a later Roman addition to the Greek story), his mother, the sea-nymph Thetis, wanted to make her son immortal. When he was an infant, she took him to the River Styx, which formed the boundary between the Earth and the Underworld.

  • The Dip: Thetis held the baby by his left heel and dipped his entire body into the magical waters. Every part of him that the water touched became invulnerable to injury.

  • The Dry Spot: Because she was holding him by the heel, that specific patch of skin remained dry. It was the only "human" part of him left—the literal and metaphorical gap in his armor.

The "junk knowledge" often ignores how he actually died: during the siege of Troy, the Trojan prince Paris (guided by the god Apollo) shot a poisoned arrow that struck Achilles exactly in that unprotected heel. The greatest warrior in history was brought down by a wound to the lowest part of his body.

Fast Facts

  • The "Achilles Tendon": In 1693, the Flemish anatomist Philip Verheyen was the first to name the large tendon at the back of the ankle the tendo Achillis. He allegedly named it after himself initially, then changed it to the mythological name after a period of self-reflection (or perhaps after injuring his own).

  • Homer’s Silence: Interestingly, in the original Iliad by Homer, Achilles is not invulnerable. He is just a very, very good soldier who eventually dies in battle. The "dipping in the Styx" part was added by the Roman poet Statius in the 1st century AD.

  • The Modern Weakness: In cybersecurity, an "Achilles Heel" is often a single line of legacy code or an unpatched server that leaves an entire multi-billion dollar network open to hackers.

References

  • Homer. (c. 8th Century BC). The Iliad. (Classical Greek Epic).

  • Statius, P. P. (c. 96 AD). The Achilleid. (Roman Epic).

  • Verheyen, P. (1693). Corporis Humani Anatomia. (First anatomical naming of the tendon).

  • Hamilton, E. (1942). Mythology: Timeless Tales of Gods and Heroes. Little, Brown and Company.