featherless biped
A human being.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“The philosopher famously defined a human as a featherless biped.”
“Every featherless biped in this room needs to sign the visitor log.”
“In his biology lecture, the professor jokingly referred to his students as featherless bipeds to illustrate an ancient definition.”
“The science fiction writer described the alien's first encounter with a featherless biped to show how strange humans look to outsiders.”
“While the ancient thinker sought to categorize life with precision, his description of man as a mere featherless biped remains a curious relic of early logic.”
From the dialogue *Statesman* by the philosopher Plato (427–347 B.C.E.), who sought a precise taxonomy for the human race. The Greek text records the necessity of dividing walking animals into bipeds and quadrupeds, noting that as humans shared the bipedal category with birds, a further distinction was required.
The resulting classification divided the biped class into the feathered and the featherless. The phrase remains a testament to the classical urge to define humanity by what it lacks, rather than what it possesses.
Last updated August 10, 2026