Like her Delphic companion, the Libyan Sibyl also turns away from the book she holds. Unlike her, however, she appears in a more intricate, even unstable posture, poised in an almost dance-like motion — apparently caught in the process of placing the tome on the table, or removing it from there. Indeed, it’s difficult to determine if the protagonist plans to close or open the book: a state of tension and uncertainty that echoes the tension with which the sibyl balances her toes on the very edge of the precipice.
Delphic and Libyan sibyls are notably younger than their Persian and Cumaean sisters — and they both seem consumed more by the physicality of movement immediately preceding or following the act of reading, rather than by the reading itself. The other two prophetesses are depicted looking straight at the pages, in a clearly more static, focused representation. It’s possible that Michelangelo wished to contrast the pairs as a way to reassert the common wisdom that youth and learning do not go hand in hand. It’s possible that he wished to suggest a different kind of symbolism.
For instance, the gesture of turning away can be viewed as a betrayal of ignorance: having knowledge (carrying it in one’s hands), yet being unable to apply it in the right direction (see the truth) — this is in fact a common Christian interpretation of ancient, particularly ancient Greek wisdom. The church embraced many Platonic and Aristotelean ideas and concepts — yet the philosophers who originated them remain “misguided,” having not received the guidance of Christ.
Hence these gestures put forth a broad allegory on paganism. Michelangelo, who was a devout catholic, shows that on the one hand early thought deserves credit but, on the other, it can only be considered as an intermediate stage on the way to loftier religious truths of Christianity.
In terms of composition, the Libyan sibyl could be one of the artist’s most sophisticated single-figure designs on the entire ceiling. It contains a series of motions, rhythms, and repetitions — spreading in all directions and dimensions — that’s difficult to grasp with one glance, as a single whole. Compositional complexity transpires from geometrical shapes described by various body parts, from the linear vectors of the arms and the legs, and from the juxtaposition of these elements in space.
*this article has been edited at a later date