I correlated Libra with Enneagram Type 1 because I remember an image in the book by Riso and Hudson, Personality Types, which displayed an image of a person holding a balance (the symbol for Libra), and so I decided that Libra did indeed correspond to Extraverted Thinking aided by Intuition.
Capricorn is ruled by the planet of Saturn, which is exalted in Libra, so that's how I decided to type Capricorn in 1, too, as ESTJ. Enneagram 1 corresponds to Extraverted Thinking.
“There are two novels that can change a bookish fourteen-year old’s life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs.” ~ John Rogers