This book is the first complete English translation of Hasdai Crescas's Light of the Lord, widely acknowledged as a seminal work of medieval Jewish philosophy, one second in importance only to Maimonides' Guide of the Perplexed. In it Crescas takes on not only Maimonides but, through him, Aristotle, and challenges views of physics and metaphysics that had become entrenched in medieval thought. Once the Aristotelian underpinnings of medieval thought are dislodged, Crescas introduces alternative physical views and reinstates the classical Jewish God as a God of love and benefaction rather than a self-intellecting intellect. The end for humankind then is to become attached in love to the God of love through devoted service.