*The Duties of the Heart* is an 11th-century Jewish ethical treatise by Rabbi Bachye ibn Bakoda, written originally in Arabic and here presented in a partial English translation by Edwin Collins; it belongs to the tradition of medieval Andalusian Jewish philosophy that synthesized Greek, Arab, and Biblical thought. The work's central argument is that ethics must be grounded not in outward religious observance but in the inner life — the perfection of character and intention — since an act is morally significant only insofar as it expresses the state of the soul behind it. Bachye proceeds entirely by reason and observation rather than from scriptural authority, opening by subjecting the existence of God to rational proof, then building upward through gratitude, humility, and contemplation toward a love of God so complete that right conduct follows automatically, without need of external reward, punishment, or commandment. The translator's introduction makes a pointed civilizational claim: that Western culture owes its sense of physical beauty and logical form to Greece, but that the two ideas most essential to modern ethics — the sanctity of human life and the universal authority of moral law — are entirely absent even from Plato, and derive solely from Hebrew moral teaching as transmitted through Judaism, Christianity, and Islam. Collins positions the work as a corrective to a spiritually depleted Western modernity, arguing that the Orient supplies the "chlorophyl" of moral and spiritual nourishment that Western material civilization cannot generate on its own. The result is both a philosophical text and a quasi-missionary introduction, framing Bachye as a timeless teacher of character formation whose rationalist yet mystical synthesis speaks beyond any single religious tradition.