Thomas Aquinas was a 13th-century philosopher and theologian known for his influential works in Christian thought. He sought to reconcile faith and reason, arguing that both could lead to truth. His most famous work, Summa Theologica, explores various aspects of theology, ethics, and philosophy, making complex ideas accessible to many. Aquinas is often associated with the Scholasticism movement, which emphasized critical thinking and debate. He introduced the concept of the "Five Ways" to prove the existence of God, using logical arguments based on observation and experience. His ideas continue to shape modern philosophy and theology today.