The blind leading the blind
"The blind leading the blind" is an idiom and a metaphor in the form of a parallel phrase. It describes a situation where a person ignorant of a given subject gets advice and help from someone just as ignorant.
History
The idiom can be traced back to the Upanishads, which were written around 800 BCEA similar metaphor exists in the Buddhist Pali Canon, composed in North India, and preserved orally until it was committed to writing during the Fourth Buddhist Council in Sri Lanka in 29 BCE.
A similar expression appears in Horace : caecus iter monstrare uelit. Horace was the leading Roman lyric poet during the time of Augustus
The phrase also features in the New Testament. It is mentioned several times in the gospels, with similar stories appearing in Matthew, Luke and the non-canonical gospel of Thomas. It possibly reached the evangelists via the hypothesised Q source.
Sextus Empiricus compares ignorant teachers and blind guides in his Outlines of Scepticism:
The phrase appears in Adagia, an annotated collection of Greek and Latin proverbs compiled during the Renaissance by Dutch humanist Desiderius Erasmus Roterodamus. The first edition, Collectanea Adagiorum, was published in Paris in 1500 CE.
Augustine of Hippo, a Catholic theologian, writes ″Vae caecis ducentibus! Vae caecis sequentibus!,″ Latin for, "woe to the blind that lead, woe to the blind that follow."