Why is the cosmos intellectually accessible to the human mind? A host of philosophers, theologians, scientists, and mathematicians of the Great Western Tradition have been struck by the uncanny interconnection between three fundamentally distinct domains of reality: nature, mathematics, and the human mind. This resonance has been discussed since antiquity and often attributed to a transcendent rational source of both material and immaterial aspects of reality. Johannes Kepler, a devout Christian who was greatly influenced by this intellectual tradition, was instrumental in transforming classical astronomy into a true celestial physics. He was convinced that a tripartite harmony of archetype, copy, and image explained the interconnections that made his natural philosophy possible-that allowed him to share in God's own thoughts. Rather than being diminished by the past few centuries of scientific progress, Keplerian natural theology is a more robust explanation of cosmic comprehensibility than ever before.