Complex sentence: The blind leading the blind is an idiom and a metaphor which can be traced back to the Upanishads, and also appears in the Buddhist Pali Canon, Horace and the Bible.
Split into simpler sentences: The blind leading the blind is an idiom and a metaphor which can be traced back to The Upanishads. It also appears in the Budhist Pali Canon, Horace and the Bible.